Wrap all SQLCommand objects in using blocks.

Improve button layout calculation and centre button images.
Rewrite download thread logic.
Enable resync timer.
Replace Command.ExecuteNonQuery and Command.ExecuteScalar with calls to DBExecuteNonQuery and DBExecuteScalar wherever possible.
Remove unnecessary ExecuteNonQuery calls from before ExecuteReader calls in export form.
Add database write lock and wrap all ExecuteNonQuery calls and transactions with it.
Move MAXDbPath and MAXDbFilePath to Globals and set at startup.
Add migration to add database indexes, change log id to autoincrement and add Download column to batches.
Modify RESTRequest to set Result parameter to null on 404 errors.
Fixed button paint.

BulkPrinting/BulkPrinting/BatchForm.cs

 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
-using System.Data;
-using System.Drawing;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using System.Windows.Forms;
-using System.IO;
-using System.Net;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Serialization;
 using System.Data.SQLite;
-using System.Threading;
+using System.Diagnostics;
+using System.Drawing;
 using System.Globalization;
+using System.Threading;
+using System.Windows.Forms;
 
 namespace BulkPrinting
 {
     public partial class BatchForm : ObservedForm
     {
-        EventWaitHandle LoadingThreadEvent;
         Thread LoadingThread;
+        readonly object LoadingThreadLock = new object();
+        bool CheckForNewBatches;
+        bool RetryDownloads;
 
         public BatchForm()
         {
         {
             Dictionary<int, BatchEvent> BatchEvents = new Dictionary<int, BatchEvent>();
             string Sql = "Select COUNT(v.BatchId) AS Total, v.BatchId,l.EventType,l.Retry FROM Voucher v LEFT JOIN Logs l on v.Id = l.VoucherId WHERE l.EventType in (@printevent,@exportevent) GROUP BY v.BatchId,l.EventType,l.Retry ORDER BY BatchId";
-            SQLiteCommand Command = new SQLiteCommand(Sql, Globals.DBConnection);
-            Command.Parameters.Add(new SQLiteParameter("@printevent", VendorEvent.VendorEventType.PrintVoucher));
-            Command.Parameters.Add(new SQLiteParameter("@exportevent", VendorEvent.VendorEventType.ExportVoucher));
-            using (SQLiteDataReader read = Command.ExecuteReader())
+            using (var Command = new SQLiteCommand(Sql, Globals.DBConnection))
             {
-                while (read.Read())
+                Command.Parameters.AddWithValue("@printevent", VendorEvent.VendorEventType.PrintVoucher);
+                Command.Parameters.AddWithValue("@exportevent", VendorEvent.VendorEventType.ExportVoucher);
+                using (SQLiteDataReader read = Command.ExecuteReader())
                 {
-                    int BatchId = int.Parse(read["BatchId"].ToString());
-                    if (!BatchEvents.ContainsKey(BatchId))
-                    {
-                        BatchEvents.Add(BatchId, new BatchEvent());
-                    }
-                    if (read["EventType"].ToString() == "6")
+                    while (read.Read())
                     {
-                        if (read["Retry"].ToString() == "True")
+                        int BatchId = int.Parse(read["BatchId"].ToString());
+                        if (!BatchEvents.ContainsKey(BatchId))
                         {
-                            BatchEvents[BatchId].ReprintCount += int.Parse(read["Total"].ToString());
+                            BatchEvents.Add(BatchId, new BatchEvent());
                         }
-                        else
+                        if (read["EventType"].ToString() == "6")
                         {
-                            BatchEvents[BatchId].PrintCount += int.Parse(read["Total"].ToString());
+                            if (read["Retry"].ToString() == "True")
+                            {
+                                BatchEvents[BatchId].ReprintCount += int.Parse(read["Total"].ToString());
+                            }
+                            else
+                            {
+                                BatchEvents[BatchId].PrintCount += int.Parse(read["Total"].ToString());
+                            }
+                        }
+                        else if (read["EventType"].ToString() == "8")
+                        {
+                            BatchEvents[BatchId].ExportCount += int.Parse(read["Total"].ToString());
                         }
-                    }
-                    else if (read["EventType"].ToString() == "8")
-                    {
-                        BatchEvents[BatchId].ExportCount += int.Parse(read["Total"].ToString());
                     }
                 }
             }
             if (CanOrder) dgvBatches.Columns.Add("RequestedQuantity", "Quantity Ordered");
             dgvBatches.Columns.Add("DeliveredQuantity", "Quantity Delivered");
             if (CanOrder) dgvBatches.Columns.Add("ReadyForDownload", "Batch Ready for Download");
+            dgvBatches.Columns.Add("Downloaded", "Downloaded");
             dgvBatches.Columns.Add("PrintedQuantity", "Quantity Printed");
             if (CanExport) dgvBatches.Columns.Add("Exported", "Exported Batch");
-            Sql = "Select Id,OrderDate,OrderReference,InternalReference,NetworkName,ProductDescription,VoucherType,FaceValue,RequestedQuantity,DeliveredQuantity,ReadyForDownload From Batch WHERE OrderDate BETWEEN @startdate AND @enddate";
-
+            Sql = "Select Id,OrderDate,OrderReference,InternalReference,NetworkName,ProductDescription,VoucherType,FaceValue,RequestedQuantity,DeliveredQuantity,ReadyForDownload,Downloaded From Batch WHERE OrderDate BETWEEN @startdate AND @enddate";
 
+            //Sql = "Select Id,OrderDate,OrderReference,InternalReference,NetworkName,ProductDescription,VoucherType,FaceValue,RequestedQuantity,DeliveredQuantity,ReadyForDownload,Downloaded,(SELECT COUNT(*) FROM Voucher WHERE Voucher.BatchId=Batch.Id) AS VoucherCount From Batch WHERE OrderDate BETWEEN @startdate AND @enddate";
+            //dgvBatches.Columns.Add("VoucherCount", "Voucher Count");
 
-            SQLiteCommand comm = new SQLiteCommand(Sql, Globals.DBConnection);
 
-            CultureInfo IVC = CultureInfo.InvariantCulture;
-            comm.Parameters.Add(new SQLiteParameter("@startdate", dtpFilterStartDate.Value.Date.ToString("yyyy-MM-dd 00:00:00", IVC)));
-            comm.Parameters.Add(new SQLiteParameter("@enddate", dtpFilterEndDate.Value.Date.ToString("yyyy-MM-dd 23:59:59", IVC)));
-
-
-            lblLoading.Hide();
-            using (SQLiteDataReader read = comm.ExecuteReader())
+            using (var Command = new SQLiteCommand(Sql, Globals.DBConnection))
             {
-                while (read.Read())
-                {
-                    int BatchId = int.Parse(read["Id"].ToString());
-                    if (!BatchEvents.ContainsKey(BatchId))
-                    { //For batches with no events
-                        BatchEvents.Add(BatchId, new BatchEvent());
-                    }
-                    int DeliveredQuantity = int.Parse(read["DeliveredQuantity"].ToString());
+                CultureInfo IVC = CultureInfo.InvariantCulture;
+                Command.Parameters.AddWithValue("@startdate", dtpFilterStartDate.Value.Date.ToString("yyyy-MM-dd 00:00:00", IVC));
+                Command.Parameters.AddWithValue("@enddate", dtpFilterEndDate.Value.Date.ToString("yyyy-MM-dd 23:59:59", IVC));
 
-                    //Filters to exclude rows that don't match
-                    if (rdoFilterPrinted.Checked)
+                lblLoading.Hide();
+                using (SQLiteDataReader read = Command.ExecuteReader())
+                {
+                    while (read.Read())
                     {
-                        if (BatchEvents[BatchId].PrintCount == 0)
+                        int BatchId = int.Parse(read["Id"].ToString());
+                        if (!BatchEvents.ContainsKey(BatchId))
+                        { //For batches with no events
+                            BatchEvents.Add(BatchId, new BatchEvent());
+                        }
+                        int DeliveredQuantity = int.Parse(read["DeliveredQuantity"].ToString());
+
+                        //Filters to exclude rows that don't match
+                        if (rdoFilterPrinted.Checked)
                         {
-                            continue;
+                            if (BatchEvents[BatchId].PrintCount == 0)
+                            {
+                                continue;
+                            }
                         }
-                    }
-                    if (rdoFilterUnprinted.Checked) {
-                        if (BatchEvents[BatchId].PrintCount >= DeliveredQuantity)
+                        if (rdoFilterUnprinted.Checked)
                         {
-                            continue;
+                            if (BatchEvents[BatchId].PrintCount >= DeliveredQuantity)
+                            {
+                                continue;
+                            }
                         }
-                    }
-                    if (rdoFilterReprinted.Checked) {
-                        if (BatchEvents[BatchId].ReprintCount == 0)
+                        if (rdoFilterReprinted.Checked)
                         {
-                            continue;
+                            if (BatchEvents[BatchId].ReprintCount == 0)
+                            {
+                                continue;
+                            }
                         }
-                    }
-                    if (rdoFilterExported.Checked)
-                    {
-                        if (BatchEvents[BatchId].ExportCount == 0)
+                        if (rdoFilterExported.Checked)
                         {
-                            continue;
+                            if (BatchEvents[BatchId].ExportCount == 0)
+                            {
+                                continue;
+                            }
                         }
-                    }
-                    else {
-                        if (BatchEvents[BatchId].ExportCount > 0)
+                        else
                         {
-                            continue;
+                            if (BatchEvents[BatchId].ExportCount > 0)
+                            {
+                                continue;
+                            }
                         }
-                    }
 
-                    var BatchRow = new object[] {
-                        BatchId,
-                        read["OrderDate"] };
-                    if (CanOrder)
-                    {
-                        BatchRow = BatchRow.Concat(new[] { read["OrderReference"] }).ToArray();
-                        BatchRow = BatchRow.Concat(new[] { read["InternalReference"] }).ToArray();
-                    }
-                    BatchRow = BatchRow.Concat(new[] { read["NetworkName"].ToString() }).ToArray();
-                    BatchRow = BatchRow.Concat(new[] { read["ProductDescription"].ToString() }).ToArray();
-                    BatchRow = BatchRow.Concat(new[] { Enum.Parse(typeof(Vouchertype), read["VoucherType"].ToString()).ToString() }).ToArray();
-                    BatchRow = BatchRow.Concat(new[] { "R" + ((decimal)read["FaceValue"]).ToString("0.##") }).ToArray();
+                        var BatchRow = new List<object>
+                            {
+                                BatchId,
+                                read["OrderDate"]
+                            };
+                        if (CanOrder)
+                        {
+                            BatchRow.Add(read["OrderReference"]);
+                            BatchRow.Add(read["InternalReference"]);
+                        }
+                        BatchRow.Add(read["NetworkName"].ToString());
+                        BatchRow.Add(read["ProductDescription"].ToString());
+                        BatchRow.Add(Enum.Parse(typeof(Vouchertype), read["VoucherType"].ToString()).ToString());
+                        BatchRow.Add("R" + ((decimal)read["FaceValue"]).ToString("0.##"));
+
+                        if (CanOrder)
+                            BatchRow.Add(read["RequestedQuantity"]);
 
-                    
-                    if (CanOrder)
-                        BatchRow = BatchRow.Concat(new[] { read["RequestedQuantity"] }).ToArray();
+                        BatchRow.Add(read["DeliveredQuantity"]);
 
-                    BatchRow = BatchRow.Concat(new[] { read["DeliveredQuantity"] }).ToArray();
+                        if (CanOrder)
+                            BatchRow.Add(((bool)read["ReadyForDownload"] == true ? "Yes" : "No"));
 
-                    if (CanOrder)
-                        BatchRow = BatchRow.Concat(new[] { ((bool)read["ReadyForDownload"] == true ? "Yes" : "No") }).ToArray();
+                        BatchRow.Add((bool)read["Downloaded"] ? "Yes" : "No");
+                        BatchRow.Add((object)BatchEvents[BatchId].PrintCount);
 
-                    BatchRow = BatchRow.Concat(new[] { (object)BatchEvents[BatchId].PrintCount }).ToArray();
+                        if (CanExport)
+                            BatchRow.Add((BatchEvents[BatchId].ExportCount > 0 ? "Exported" : ""));
 
-                    if (CanExport)
-                        BatchRow = BatchRow.Concat(new[] { (BatchEvents[BatchId].ExportCount >0?"Exported":"") }).ToArray();
+                        //BatchRow.Add(read["VoucherCount"]);
 
-                    dgvBatches.Rows.Add(BatchRow);
+                        dgvBatches.Rows.Add(BatchRow.ToArray());
+                    }
+                    dgvBatches.Sort(dgvBatches.Columns["OrderDate"], ListSortDirection.Descending);
                 }
-                dgvBatches.Sort(dgvBatches.Columns["OrderDate"], ListSortDirection.Descending);
             }
         }
 
             if (!Utility.CheckUserAccess(Utility.UserPermissions.BulkViewPins))
                 RightButtonList.Remove(this.btnViewPINs);
 
-            int ButtonX = 12;
+            int ButtonX = btnLogout.Location.X;
+            int ButtonY = btnLogout.Location.Y;
+            int ButtonSpacing = btnOrderReport.Location.X - ButtonX;
             foreach (Button b in LeftButtonList)
             {
-                b.Location = new Point(ButtonX, 0);
+                b.Location = new Point(ButtonX, ButtonY);
                 b.Show();
-                ButtonX += 106;
+                ButtonX += ButtonSpacing;
             }
 
-            ButtonX = pnlSplitGrids.Width - 378;
+            ButtonX = btnReprint.Location.X;
             RightButtonList.Reverse();
             foreach (Button b in RightButtonList)
             {
-                b.Location = new Point(ButtonX, 0);
+                b.Location = new Point(ButtonX, ButtonY);
                 b.Show();
-                ButtonX -= 106;
+                ButtonX -= ButtonSpacing;
             }
 
             lblLoading.Show();
             dtpFilterStartDate.Value = DateTime.Now.AddMonths(-3);
             Globals.OpenBatches = new List<int>();
 
-            LoadingThreadEvent = new EventWaitHandle(true, EventResetMode.AutoReset);
-            LoadingThread = new Thread(() =>
+            RetryDownloads = true;
+            CheckForNewBatches = true;
+
+            LoadingThread = new Thread(LoadingThreadWorker);
+            LoadingThread.Start();
+            Utility.InitialiseUserLimits(Globals.DBConnection);
+            ReSyncTimer.Enabled = true;
+        }
+
+        private void LoadingThreadWorker()
+        {
+            const int voucherPageSize = 5000;
+            var conn = Globals.DBConnection;
+            //using (var conn = Utility.OpenDBConnection())
             {
                 Invoke(new Action(() =>
                 {
-                    this.Enabled = false;
                     PopulateGrid();
-                    this.Enabled = true;
                 }));
 
-                while (LoadingThreadEvent.WaitOne())
+                var lastSyncedBatchId = Utility.GetSavedParameterAsInt(conn, "LastSyncedBatchId");
+
+                bool skipNewBatchCheck = false;
+                while (true)
                 {
+                    bool forceNewBatchCheck;
+                    lock (LoadingThreadLock)
+                    {
+                        while (!RetryDownloads)
+                        {
+                            Monitor.Wait(LoadingThreadLock);
+                        }
+                        forceNewBatchCheck = CheckForNewBatches;
+                        RetryDownloads = false;
+                        CheckForNewBatches = false;
+                    }
                     if (Globals.SessionMode == SessionModes.Online)
                     {
-                        Utility.SyncAllBatches();
-                        Invoke(new Action(() =>
+                        Debug.WriteLine("Checking for downloads");
+
+                        if (forceNewBatchCheck)
+                        {
+                            skipNewBatchCheck = false;
+                        }
+
+                        // Check for new batches if required.
+                        var refreshGrid = false;
+                        try
+                        {
+                            while (!skipNewBatchCheck)
+                            {
+                                Debug.WriteLine("Querying batches");
+                                Page<Batch> BatchPage = new Page<Batch>();
+                                if (Utility.RESTRequest(ref BatchPage, String.Format("/api/batches/?lastBatchId={0}", lastSyncedBatchId)))
+                                {
+                                    if (BatchPage.Items.Count == 0)
+                                    {
+                                        // No more new batches, so stop checking until an order is placed.
+                                        skipNewBatchCheck = true;
+                                    }
+                                    else
+                                    {
+                                        foreach (var batch in BatchPage.Items)
+                                        {
+                                            refreshGrid = true;
+                                            Utility.SaveBatch(conn, batch);
+                                            lastSyncedBatchId = batch.Id;
+                                            if (!Utility.UpdateSavedParameter(conn, "LastSyncedBatchId", lastSyncedBatchId))
+                                            {
+                                                // Shouldn't happen.
+                                                throw new Exception("Failed to update LastSyncedBatchId");
+                                            }
+                                        }
+                                    }
+                                }
+                                else
+                                {
+                                    // Error, so leave skipNewBatchCheck unchanged.
+                                    break;
+                                }
+                            }
+                        }
+                        catch (Exception e)
+                        {
+                            Debug.WriteLine("Error while downloading batches");
+                            Debug.WriteLine(e.ToString());
+                        }
+
+                        if (refreshGrid)
                         {
-                            PopulateGrid();
-                        }));
+                            Invoke(new Action(() =>
+                            {
+                                PopulateGrid();
+                            }));
+                        }
+
+                        // Continue downloading incomplete batches if any.
+                        try
+                        {
+                            using (var command = new SQLiteCommand(
+                                "SELECT Id FROM Batch WHERE Downloaded=0 ORDER BY Downloaded, Id",
+                                conn))
+                            {
+                                using (SQLiteDataReader row = command.ExecuteReader())
+                                {
+                                    while (row.Read())
+                                    {
+                                        refreshGrid = false;
+
+                                        int batchId = (int)row["Id"];
+                                        try
+                                        {
+                                            Batch batch = new Batch();
+                                            if (Utility.RESTRequest(ref batch, String.Format("/api/batches/{0}", batchId)))
+                                            {
+                                                refreshGrid = true;
+                                                Utility.SaveBatch(conn, batch);
+
+                                                if (batch.ReadyForDownload)
+                                                {
+                                                    long result = (long)Utility.DBExecuteScalar(conn,
+                                                        "SELECT COUNT(*) FROM Voucher WHERE BatchId=@BatchId",
+                                                        new SQLiteParameter("@BatchId", batchId));
+                                                    int voucherCount = (int)result;
+
+                                                    while (voucherCount < batch.DeliveredQuantity)
+                                                    {
+                                                        Debug.WriteLine(String.Format("Downloading vouchers for batch {0} (got {1})", batchId, voucherCount));
+
+                                                        int page = voucherCount / voucherPageSize + 1;
+                                                        int offset = voucherCount % voucherPageSize;
+
+                                                        Page<Voucher> voucherPage = new Page<Voucher>();
+                                                        if (!Utility.RESTRequest(ref voucherPage, String.Format("/api/batches/{0}/vouchers/?page={1}&pageSize={2}", batchId, page, voucherPageSize)))
+                                                        {
+                                                            break;
+                                                        }
+                                                        if (voucherPage.Items.Count == 0)
+                                                        {
+                                                            throw new Exception(String.Format("Too few vouchers were returned for batch {0}", batchId));
+                                                        }
+
+                                                        Debug.WriteLine(String.Format("Downloaded vouchers for batch {0} (got {1})", batchId, voucherCount + voucherPage.Items.Count));
+
+                                                        lock (Globals.DBWriteLock)
+                                                        {
+                                                            using (var trans = conn.BeginTransaction())
+                                                            {
+                                                                using (var insert = new SQLiteCommand(
+                                                                    "INSERT INTO Voucher (Id, SequenceNumber, ExpiryDate, Serial, EncryptedPIN, BatchId)" +
+                                                                                 "VALUES (@Id,@SequenceNumber,@ExpiryDate,@Serial,@EncryptedPin,@BatchId)",
+                                                                    conn, trans))
+                                                                {
+                                                                    for (var i = offset; i < voucherPage.Items.Count; i++)
+                                                                    {
+                                                                        var voucher = voucherPage.Items[i];
+                                                                        if (voucher.SequenceNumber != voucherCount + 1)
+                                                                        {
+                                                                            throw new Exception(String.Format("Vouchers for batch {0} are not sequential: expecting {1}, got {2}", batchId, voucherCount + 1, voucher.SequenceNumber));
+                                                                        }
+                                                                        insert.Parameters.Clear();
+                                                                        insert.Parameters.AddWithValue("@Id", voucher.Id);
+                                                                        insert.Parameters.AddWithValue("@SequenceNumber", voucher.SequenceNumber);
+                                                                        insert.Parameters.AddWithValue("@ExpiryDate", voucher.ExpiryDate.Date);
+                                                                        insert.Parameters.AddWithValue("@Serial", voucher.Serial);
+                                                                        insert.Parameters.AddWithValue("@EncryptedPIN", voucher.EncryptedPIN);
+                                                                        insert.Parameters.AddWithValue("@BatchId", batchId);
+                                                                        insert.ExecuteNonQuery();
+                                                                        voucherCount++;
+                                                                    }
+                                                                }
+                                                                trans.Commit();
+                                                            }
+                                                        }
+
+                                                        Debug.WriteLine(String.Format("Inserted vouchers for batch {0}", batchId));
+                                                    }
+
+                                                    if (voucherCount > batch.DeliveredQuantity)
+                                                    {
+                                                        throw new Exception("Batch contains more than the specified number of vouchers");
+                                                    }
+                                                    else
+                                                    {
+                                                        Debug.WriteLine(String.Format("Batch {0} complete", batchId));
+
+                                                        Utility.DBExecuteNonQuery(conn,
+                                                            "UPDATE Batch SET Downloaded=1 WHERE Id=@BatchId",
+                                                            new SQLiteParameter("@BatchId", batchId));
+                                                    }
+                                                }
+                                            }
+                                            else if (batch == null)
+                                            {
+                                                // Batch will only be null if we got a 404.
+                                                Debug.WriteLine(String.Format("Removing deleted batch {0}", batchId));
+
+                                                Utility.DBExecuteNonQuery(conn,
+                                                    "DELETE FROM Voucher WHERE BatchId=@BatchId",
+                                                    new SQLiteParameter("@BatchId", batchId));
+
+                                                Utility.DBExecuteNonQuery(conn,
+                                                    "DELETE FROM Batch WHERE Id=@BatchId",
+                                                    new SQLiteParameter("@BatchId", batchId));
+
+                                                refreshGrid = true;
+                                            }
+                                        }
+                                        catch (Exception e)
+                                        {
+                                            Debug.WriteLine(String.Format("Error while downloading vouchers for batch {0}", batchId));
+                                            Debug.WriteLine(e.ToString());
+                                        }
+
+                                        if (refreshGrid)
+                                        {
+                                            Invoke(new Action(() =>
+                                            {
+                                                PopulateGrid();
+                                            }));
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                        catch (Exception e)
+                        {
+                            Debug.WriteLine("Error while downloading vouchers");
+                            Debug.WriteLine(e.ToString());
+                        }
                     }
                 }
-            });
-            LoadingThread.Start();
-            Utility.InitialiseUserLimits();
+            }
+        }
+
+        public void NewBatchAvailable()
+        {
+            lock (LoadingThreadLock)
+            {
+                RetryDownloads = true;
+                CheckForNewBatches = true;
+                Monitor.Pulse(LoadingThreadLock);
+            }
         }
 
         private void btnOrder_Click(object sender, EventArgs e)
             }
 
             int DeliveredVoucherCount = (int)dgvBatches.SelectedRows[0].Cells[dgvBatches.Columns["DeliveredQuantity"].Index].Value;
-            string Sql = "SELECT COUNT(*) FROM Voucher WHERE BatchId=@id";
-            SQLiteCommand Command = new SQLiteCommand(Sql, Globals.DBConnection);
-            Command.Parameters.Add(new SQLiteParameter("@id", BatchID));
-            int DownloadedVoucherCount = Convert.ToInt32(Command.ExecuteScalar());
+            int DownloadedVoucherCount = Convert.ToInt32(Utility.DBExecuteScalar(Globals.DBConnection,
+                "SELECT COUNT(*) FROM Voucher WHERE BatchId=@id",
+                new SQLiteParameter("@id", BatchID)));
             if (DownloadedVoucherCount < DeliveredVoucherCount) {
                 MessageBox.Show(string.Format("Batch {0} has not finished downloading.\nDownloaded {1} of {2} vouchers in batch.",BatchID,DownloadedVoucherCount,DeliveredVoucherCount), "Cannot open print dialog", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                 return;
             if ((LoadingThread != null) && (LoadingThread.IsAlive))
             {
                 LoadingThread.Abort();
+                LoadingThread.Join();
             }
             Utility.Logout();
         }
                 MessageBox.Show("This batch has been exported previously. Exported batches cannot be printed.", "Cannot print batch", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                 return;
             }
-            SQLiteCommand Command = new SQLiteCommand("SELECT COUNT(*) FROM Voucher v LEFT JOIN Logs l ON v.Id = l.VoucherId AND l.EventType = @eventtype WHERE l.VoucherId IS NOT NULL AND v.BatchId=@batchid AND Retry=0", Globals.DBConnection);
-            Command.Parameters.Add(new SQLiteParameter("@batchid", BatchID));
-            Command.Parameters.Add(new SQLiteParameter("@eventtype", VendorEvent.VendorEventType.PrintVoucher));
-            int PrintCount = int.Parse(Command.ExecuteScalar().ToString());
+            int PrintCount = int.Parse(Utility.DBExecuteScalar(Globals.DBConnection,
+                "SELECT COUNT(*) FROM Voucher v LEFT JOIN Logs l ON v.Id = l.VoucherId AND l.EventType = @eventtype WHERE l.VoucherId IS NOT NULL AND v.BatchId=@batchid AND Retry=0",
+                new SQLiteParameter("@batchid", BatchID),
+                new SQLiteParameter("@eventtype", VendorEvent.VendorEventType.PrintVoucher)).ToString());
 
             if (PrintCount == 0) {
                 MessageBox.Show("You can only use the Reprint feature for vouchers that have already been printed. Please choose a batch with previously printed vouchers.", "Cannot reprint batch", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
             }
 
             int DeliveredVoucherCount = (int)dgvBatches.SelectedRows[0].Cells[dgvBatches.Columns["DeliveredQuantity"].Index].Value;
-            string Sql = "SELECT COUNT(*) FROM Voucher WHERE BatchId=@id";
-            Command = new SQLiteCommand(Sql, Globals.DBConnection);
-            Command.Parameters.Add(new SQLiteParameter("@id", BatchID));
-            int DownloadedVoucherCount = Convert.ToInt32(Command.ExecuteScalar());
+            int DownloadedVoucherCount = Convert.ToInt32(Utility.DBExecuteScalar(Globals.DBConnection,
+                "SELECT COUNT(*) FROM Voucher WHERE BatchId=@id",
+                new SQLiteParameter("@id", BatchID)));
             if (DownloadedVoucherCount < DeliveredVoucherCount)
             {
                 MessageBox.Show(string.Format("Batch {0} has not finished downloading.\nDownloaded {1} of {2} vouchers in batch.", BatchID, DownloadedVoucherCount, DeliveredVoucherCount), "Cannot open print dialog", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
             if (!b.Enabled)
             {
                 e.Graphics.Clear(Color.Gray);
-                e.Graphics.DrawImage(b.BackgroundImage, e.ClipRectangle.X, e.ClipRectangle.Y, e.ClipRectangle.Width, e.ClipRectangle.Height);
+                //e.Graphics.DrawImage(b.BackgroundImage, e.ClipRectangle.X, e.ClipRectangle.Y, e.ClipRectangle.Width, e.ClipRectangle.Height);
+                e.Graphics.DrawImage(b.BackgroundImage, b.ClientRectangle);
             }
         }
 
         private void ReSyncTimer_Tick(object sender, EventArgs e)
         {
-            LoadingThreadEvent.Set();
+            lock (LoadingThreadLock)
+            {
+                RetryDownloads = true;
+                Monitor.Pulse(LoadingThreadLock);
+            }
         }
     }
 }

BulkPrinting/BulkPrinting/Configuration.cs

-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using System.IO;
-
-namespace BulkPrinting
+namespace BulkPrinting
 {
     public static class Configuration
     {

BulkPrinting/BulkPrinting/ExportForm.cs

                 Sql += " AND b.NetworkName=@networkname";
             }
             Sql += " GROUP BY b.Id,b.FaceValue,b.ProductDescription,b.DeliveredQuantity";
-            SQLiteCommand Command = new SQLiteCommand(Sql, Globals.DBConnection);
-            if (cmbNetwork.SelectedItem.ToString() != "All")
+            using (var Command = new SQLiteCommand(Sql, Globals.DBConnection))
             {
-                Command.Parameters.Add(new SQLiteParameter("@networkname", cmbNetwork.SelectedItem.ToString()));
-            }
-            CultureInfo IVC = CultureInfo.InvariantCulture;
-            Command.Parameters.Add(new SQLiteParameter("@startdate", dtpStartDate.Value.Date.ToString("yyyy-MM-dd 00:00:00", IVC)));
-            Command.Parameters.Add(new SQLiteParameter("@enddate", dtpEndDate.Value.Date.ToString("yyyy-MM-dd 23:59:59", IVC)));
-            Command.Parameters.Add(new SQLiteParameter("@printevent", VendorEvent.VendorEventType.PrintVoucher));
-            Command.Parameters.Add(new SQLiteParameter("@exportevent", VendorEvent.VendorEventType.ExportVoucher));
-            Command.ExecuteNonQuery();
-            lstBatchList.Items.Clear();
-            using (SQLiteDataReader read = Command.ExecuteReader())
-            {
-                while (read.Read())
+                if (cmbNetwork.SelectedItem.ToString() != "All")
                 {
-                    if (read["Printed"].ToString() == "0")
+                    Command.Parameters.AddWithValue("@networkname", cmbNetwork.SelectedItem.ToString());
+                }
+                CultureInfo IVC = CultureInfo.InvariantCulture;
+                Command.Parameters.AddWithValue("@startdate", dtpStartDate.Value.Date.ToString("yyyy-MM-dd 00:00:00", IVC));
+                Command.Parameters.AddWithValue("@enddate", dtpEndDate.Value.Date.ToString("yyyy-MM-dd 23:59:59", IVC));
+                Command.Parameters.AddWithValue("@printevent", VendorEvent.VendorEventType.PrintVoucher);
+                Command.Parameters.AddWithValue("@exportevent", VendorEvent.VendorEventType.ExportVoucher);
+                lstBatchList.Items.Clear();
+                using (SQLiteDataReader read = Command.ExecuteReader())
+                {
+                    while (read.Read())
                     {
-                        if ((SelectedMode == ExportMode.Export && read["Exported"].ToString() != "0") ||
-                            (SelectedMode == ExportMode.Reexport && read["Exported"].ToString() == "0"))
+                        if (read["Printed"].ToString() == "0")
                         {
-                            continue;
+                            if ((SelectedMode == ExportMode.Export && read["Exported"].ToString() != "0") ||
+                                (SelectedMode == ExportMode.Reexport && read["Exported"].ToString() == "0"))
+                            {
+                                continue;
+                            }
+                            BatchItem NewBatchItem = new BatchItem();
+                            NewBatchItem.Id = int.Parse(read["Id"].ToString());
+                            NewBatchItem.Description = read["ProductDescription"].ToString();
+                            NewBatchItem.Quantity = int.Parse(read["DeliveredQuantity"].ToString());
+                            NewBatchItem.FaceValue = int.Parse(read["FaceValue"].ToString());
+                            lstBatchList.Items.Add(NewBatchItem);
                         }
-                        BatchItem NewBatchItem = new BatchItem();
-                        NewBatchItem.Id = int.Parse(read["Id"].ToString());
-                        NewBatchItem.Description = read["ProductDescription"].ToString();
-                        NewBatchItem.Quantity = int.Parse(read["DeliveredQuantity"].ToString());
-                        NewBatchItem.FaceValue = int.Parse(read["FaceValue"].ToString());
-                        lstBatchList.Items.Add(NewBatchItem);
                     }
                 }
             }
                 lblBatchType.Text = "Previously Exported Batches";
             }
             string Sql = "SELECT DISTINCT NetworkName FROM Batch";
-            SQLiteCommand Command = new SQLiteCommand(Sql, Globals.DBConnection);
-            Command.ExecuteNonQuery();
-            cmbNetwork.Items.Clear();
-            cmbNetwork.Items.Add("All");
-            using (SQLiteDataReader read = Command.ExecuteReader())
+            using (var Command = new SQLiteCommand(Sql, Globals.DBConnection))
             {
-                while (read.Read())
+                cmbNetwork.Items.Clear();
+                cmbNetwork.Items.Add("All");
+                using (SQLiteDataReader read = Command.ExecuteReader())
                 {
-                    cmbNetwork.Items.Add(read["NetworkName"]);
+                    while (read.Read())
+                    {
+                        cmbNetwork.Items.Add(read["NetworkName"]);
+                    }
                 }
             }
             cmbNetwork.SelectedItem="All";
                     List<EventLog> LogEvents = new List<EventLog>();
 
                     string Sql = "SELECT v.Id,v.ExpiryDate,v.Serial,v.EncryptedPIN,b.FaceValue,v.BatchId,v.SequenceNumber,b.ProductDescription,COUNT(l.Id) AS Exports FROM Voucher v LEFT JOIN Logs l ON v.Id = l.VoucherId AND l.EventType=@eventtype LEFT JOIN Batch b ON v.BatchId=b.Id WHERE BatchId=@batchid GROUP BY v.Id,v.ExpiryDate,v.Serial,v.EncryptedPIN,b.FaceValue,v.BatchId,v.SequenceNumber,b.ProductDescription";
-                    SQLiteCommand Command = new SQLiteCommand(Sql, Globals.DBConnection);
-
-                    foreach (BatchItem ExportBatch in lstSelectedBatches.Items)
+                    using (var Command = new SQLiteCommand(Sql, Globals.DBConnection))
                     {
-                        /*  -Id
-                            -Expiry
-                            -Serial
-                            -PIN
-                            -Face Value
-                            -BatchID
-                            -SQN
-                            -Description
-                        */
-                        if (Command.Parameters.Count == 0)
+                        foreach (BatchItem ExportBatch in lstSelectedBatches.Items)
                         {
-                            Command.Parameters.Add(new SQLiteParameter("@batchid", ExportBatch.Id));
-                            Command.Parameters.Add(new SQLiteParameter("@eventtype", VendorEvent.VendorEventType.ExportVoucher));
-                        }
-                        else
-                        {
-                            Command.Parameters[0].Value = ExportBatch.Id;
-                            Command.Parameters[1].Value = VendorEvent.VendorEventType.ExportVoucher;
-                        }
-                        // Command.Prepare(); // < -- internal
-                        Command.ExecuteNonQuery();
-                        using (StreamWriter sw = File.CreateText(Path.Combine(PathDialog.SelectedPath, "RG_" + ExportBatch.Id.ToString() + "_" + ExportBatch.Description + "_" + ExportBatch.FaceValue.ToString() + ".txt")))
-                        {
-                            sw.WriteLine("ID|Expiry|Serial|PIN|Value|BatchId|SQN|Description");
-                            using (SQLiteDataReader read = Command.ExecuteReader())
+                            /*  -Id
+                                -Expiry
+                                -Serial
+                                -PIN
+                                -Face Value
+                                -BatchID
+                                -SQN
+                                -Description
+                            */
+                            if (Command.Parameters.Count == 0)
+                            {
+                                Command.Parameters.AddWithValue("@batchid", ExportBatch.Id);
+                                Command.Parameters.AddWithValue("@eventtype", VendorEvent.VendorEventType.ExportVoucher);
+                            }
+                            else
+                            {
+                                Command.Parameters[0].Value = ExportBatch.Id;
+                                Command.Parameters[1].Value = VendorEvent.VendorEventType.ExportVoucher;
+                            }
+                            // Command.Prepare(); // < -- internal
+                            using (StreamWriter sw = File.CreateText(Path.Combine(PathDialog.SelectedPath, "RG_" + ExportBatch.Id.ToString() + "_" + ExportBatch.Description + "_" + ExportBatch.FaceValue.ToString() + ".txt")))
                             {
-                                while (read.Read())
+                                sw.WriteLine("ID|Expiry|Serial|PIN|Value|BatchId|SQN|Description");
+                                using (SQLiteDataReader read = Command.ExecuteReader())
                                 {
-                                    string DecryptedPIN = Utility.TripleDESDecrypt(read["EncryptedPIN"].ToString(), Globals.SessionVoucherKey).ToString();
-                                    string ExportRow = string.Format("{0}|{1}|{2}|{3}|{4}|{5}|{6}|{7}",
-                                                 read["Id"].ToString(),
-                                                 DateTime.Parse(read["ExpiryDate"].ToString()).ToString("dd/MM/yyyy"),
-                                                 read["Serial"].ToString(),
-                                                 DecryptedPIN,
-                                                 read["FaceValue"].ToString(),
-                                                 read["BatchId"].ToString(),
-                                                 read["SequenceNumber"].ToString(),
-                                                 read["ProductDescription"].ToString());
-                                    sw.WriteLine(ExportRow);
-                                    var ExportEvent = new EventLog();
-                                    ExportEvent.EventType = VendorEvent.VendorEventType.ExportVoucher;
-                                    ExportEvent.VoucherId = int.Parse(read["Id"].ToString());
-                                    ExportEvent.Retry = (read["Exports"].ToString() != "0");
-                                    LogEvents.Add(ExportEvent);
+                                    while (read.Read())
+                                    {
+                                        string DecryptedPIN = Utility.TripleDESDecrypt(read["EncryptedPIN"].ToString(), Globals.SessionVoucherKey).ToString();
+                                        string ExportRow = string.Format("{0}|{1}|{2}|{3}|{4}|{5}|{6}|{7}",
+                                                     read["Id"].ToString(),
+                                                     DateTime.Parse(read["ExpiryDate"].ToString()).ToString("dd/MM/yyyy"),
+                                                     read["Serial"].ToString(),
+                                                     DecryptedPIN,
+                                                     read["FaceValue"].ToString(),
+                                                     read["BatchId"].ToString(),
+                                                     read["SequenceNumber"].ToString(),
+                                                     read["ProductDescription"].ToString());
+                                        sw.WriteLine(ExportRow);
+                                        var ExportEvent = new EventLog();
+                                        ExportEvent.EventType = VendorEvent.VendorEventType.ExportVoucher;
+                                        ExportEvent.VoucherId = int.Parse(read["Id"].ToString());
+                                        ExportEvent.Retry = (read["Exports"].ToString() != "0");
+                                        LogEvents.Add(ExportEvent);
+                                    }
                                 }
                             }
                         }
-                        Utility.LogBulkEvents(LogEvents);
                     }
+                    Utility.LogBulkEvents(Globals.DBConnection, LogEvents);
                 }
                 MessageBox.Show("Vouchers Exported");
                 this.Close();

BulkPrinting/BulkPrinting/Globals.cs

 {
     public static class Globals
     {
+        public static string MaxDBPath;
+        public static string MaxDBFilePath;
+        public static readonly object DBWriteLock = new object();
         public static SessionModes SessionMode;
         public static OKResponse SessionData;
         public static string HDDSerialNumber;

BulkPrinting/BulkPrinting/Migrations.cs

 {
     class Migrations
     {
-        public static void CheckMigrations() {
-
-            string sql;
-            SQLiteCommand Command;
-            sql = "SELECT Value FROM Parameters WHERE Key = 'Migration'";
-            Command = new SQLiteCommand(sql, Globals.DBConnection);
-            var result = Command.ExecuteScalar();
+        public static void CheckMigrations(SQLiteConnection conn) {
+            var result = Utility.DBExecuteScalar(conn, "SELECT Value FROM Parameters WHERE Key = 'Migration'");
+            int startingMigration;
+            if (result == null)
+            {
+                startingMigration = 0;
+            }
+            else if (! int.TryParse((string)result, out startingMigration))
+            {
+                throw new Exception(String.Format("Invalid migration value: {0}", result));
+            }
 
-            if (result == null) {
-                Migration1();
+            if (startingMigration > 2)
+            {
+                throw new Exception("Database is for a newer version of this application. Please upgrade and try again.");
+            }
+            if (startingMigration < 1) {
+                Migration1(conn);
+            }
+            if (startingMigration < 2)
+            {
+                Migration2(conn);
             }
             //Add further migration executions here - Migration = '1', '2', '3' etc
 
             return;
         }
 
-        public static bool InitialVersion() {
-            string MaxDBPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), Configuration.MaxDataPathName);
-            string MaxDBFilePath = Path.Combine(MaxDBPath, Configuration.MaxDBFileName);
-            Globals.DBConnection = new SQLiteConnection(string.Format("Data Source={0};", MaxDBFilePath));
-            Globals.DBConnection.SetPassword(Globals.SessionDatabasePassword);
-            Globals.DBConnection.Open();
-            string sql = "CREATE TABLE Batch (" +
-                "Id INT," +
-                "OrderDate DATETIME," +
-                "OrderGuid VARCHAR(36), " +
-                "OrderReference VARCHAR(20) NOT NULL," +
-                "NetworkId INT," +
-                "NetworkName VARCHAR(20) NOT NULL," +
-                "ProductId INT," +
-                "ProductDescription VARCHAR(50)," +
-                "VoucherType INT," +
-                "FaceValue DECIMAL(10,2)," +
-                "DiscountPercentage DECIMAL(10,2)," +
-                "RequestedQuantity INT," +
-                "DeliveredQuantity INT," +
-                "Cost DECIMAL(10,2)," +
-                "ReadyForDownload BOOLEAN)";
-
-            SQLiteCommand command = new SQLiteCommand(sql, Globals.DBConnection);
-            command.ExecuteNonQuery();
-
-            sql = "CREATE TABLE Voucher(" +
-                "Id INT ," +
-                "SequenceNumber INT," +
-                "ExpiryDate DATE," +
-                "Serial VARCHAR(50)," +
-                "EncryptedPIN VARCHAR(50)," +
-                "BatchId INT)";
-
-            command = new SQLiteCommand(sql, Globals.DBConnection);
-            command.ExecuteNonQuery();
-
-            sql = "CREATE TABLE SessionData(" +
-                "Key VARCHAR(20)," +
-                "Value TEXT)";
-
-            command = new SQLiteCommand(sql, Globals.DBConnection);
-            command.ExecuteNonQuery();
-
-            sql = "CREATE TABLE Parameters(" +
-                "Key VARCHAR(20)," +
-                "Value TEXT)";
-
-            command = new SQLiteCommand(sql, Globals.DBConnection);
-            command.ExecuteNonQuery();
-
-            sql = "CREATE TABLE AccessControlTracking (" +
-                "UserID INT NOT NULL," +
-                "Permission VARCHAR(20)," +
-                "Date DATETIME," +
-                "CurrentUsage DECIMAL)";
-
-            command = new SQLiteCommand(sql, Globals.DBConnection);
-            command.ExecuteNonQuery();
-
-            sql = "CREATE TABLE Logs(" +
-                "Id INTEGER PRIMARY KEY," +
-                "UserId INT NOT NULL," +
-                "VoucherId INT," +
-                "EventDate DATETIME," +
-                "EventType VARCHAR(50)," +
-                "Retry BOOLEAN)";
-
-            command = new SQLiteCommand(sql, Globals.DBConnection);
-            command.ExecuteNonQuery();
-
-            sql = "CREATE TABLE Orders(" +
-                "Id INTEGER PRIMARY KEY," +
-                "UserId INT NOT NULL," +
-                "UserName VARCHAR(50)," +
-                "OrderDate DATETIME," +
-                "OrderCost DECIMAL," +
-                "BalanceAfterOrder DECIMAL)";
-
-            command = new SQLiteCommand(sql, Globals.DBConnection);
-            command.ExecuteNonQuery();
-
-            sql = "CREATE TABLE OrderedItems(" +
-                "Id INTEGER PRIMARY KEY," +
-                "OrderId INT NOT NULL," +
-                "Cost DECIMAL," +
-                "Quantity INT," +
-                "Description VARCHAR(50)," +
-                "ProductId)";
-
-            command = new SQLiteCommand(sql, Globals.DBConnection);
-            command.ExecuteNonQuery();
-            
-            return true; //Initial Migration doesn't trigger any others, as a Migration check is performed later in the login
+        private static bool ApplyMigrationQueries(SQLiteConnection conn, params string[] queries)
+        {
+            lock (Globals.DBWriteLock)
+            {
+                using (var trans = conn.BeginTransaction())
+                {
+                    foreach (var query in queries)
+                    {
+                        using (var command = new SQLiteCommand(query, conn, trans))
+                        {
+                            command.ExecuteNonQuery();
+                        }
+                    }
+                    trans.Commit();
+                }
+            }
+            return true;
         }
 
-        public static bool Migration1 (){
-            string sql = "ALTER TABLE Orders ADD COLUMN InternalReference VARCHAR(32)";
-            SQLiteCommand command = new SQLiteCommand(sql, Globals.DBConnection);
-            command.ExecuteNonQuery();
-
-            sql = "ALTER TABLE Batch ADD COLUMN InternalReference VARCHAR(32)";
-            command = new SQLiteCommand(sql, Globals.DBConnection);
-            command.ExecuteNonQuery();
+        public static bool InitialVersion(SQLiteConnection conn) {
+            return ApplyMigrationQueries(
+                conn,
+                "CREATE TABLE Batch (" +
+                    "Id INT," +
+                    "OrderDate DATETIME," +
+                    "OrderGuid VARCHAR(36), " +
+                    "OrderReference VARCHAR(20) NOT NULL," +
+                    "NetworkId INT," +
+                    "NetworkName VARCHAR(20) NOT NULL," +
+                    "ProductId INT," +
+                    "ProductDescription VARCHAR(50)," +
+                    "VoucherType INT," +
+                    "FaceValue DECIMAL(10,2)," +
+                    "DiscountPercentage DECIMAL(10,2)," +
+                    "RequestedQuantity INT," +
+                    "DeliveredQuantity INT," +
+                    "Cost DECIMAL(10,2)," +
+                    "ReadyForDownload BOOLEAN)",
+
+                "CREATE TABLE Voucher(" +
+                    "Id INT ," +
+                    "SequenceNumber INT," +
+                    "ExpiryDate DATE," +
+                    "Serial VARCHAR(50)," +
+                    "EncryptedPIN VARCHAR(50)," +
+                    "BatchId INT)",
+
+                "CREATE TABLE SessionData(" +
+                    "Key VARCHAR(20)," +
+                    "Value TEXT)",
+
+                "CREATE TABLE Parameters(" +
+                    "Key VARCHAR(20)," +
+                    "Value TEXT)",
+
+                "CREATE TABLE AccessControlTracking (" +
+                    "UserID INT NOT NULL," +
+                    "Permission VARCHAR(20)," +
+                    "Date DATETIME," +
+                    "CurrentUsage DECIMAL)",
+
+                "CREATE TABLE Logs(" +
+                    "Id INTEGER PRIMARY KEY," +
+                    "UserId INT NOT NULL," +
+                    "VoucherId INT," +
+                    "EventDate DATETIME," +
+                    "EventType VARCHAR(50)," +
+                    "Retry BOOLEAN)",
+
+                "CREATE TABLE Orders(" +
+                    "Id INTEGER PRIMARY KEY," +
+                    "UserId INT NOT NULL," +
+                    "UserName VARCHAR(50)," +
+                    "OrderDate DATETIME," +
+                    "OrderCost DECIMAL," +
+                    "BalanceAfterOrder DECIMAL)",
+
+                "CREATE TABLE OrderedItems(" +
+                    "Id INTEGER PRIMARY KEY," +
+                    "OrderId INT NOT NULL," +
+                    "Cost DECIMAL," +
+                    "Quantity INT," +
+                    "Description VARCHAR(50)," +
+                    "ProductId)"
+            );
+        }
 
-            //First Migration value - future values to be updated
-            sql = "INSERT INTO Parameters (Key, Value) VALUES ('Migration','1')";
-            command = new SQLiteCommand(sql, Globals.DBConnection);
-            command.ExecuteNonQuery();
+        public static bool Migration1 (SQLiteConnection conn){
+            return ApplyMigrationQueries(
+                conn,
+                "ALTER TABLE Orders ADD COLUMN InternalReference VARCHAR(32)",
+                "ALTER TABLE Batch ADD COLUMN InternalReference VARCHAR(32)",
+                "INSERT INTO Parameters (Key, Value) VALUES ('Migration','1')"
+            );
+        }
 
-            return true;
+        public static bool Migration2(SQLiteConnection conn)
+        {
+            return ApplyMigrationQueries(
+                conn,
+                "ALTER TABLE Batch ADD COLUMN Downloaded BOOLEAN",
+                "CREATE UNIQUE INDEX Batch_Id ON Batch(Id)",
+                "CREATE INDEX Batch_OrderDate ON Batch(OrderDate)",
+                "CREATE INDEX Batch_Downloaded_Id ON Batch(Downloaded, Id)",
+                "CREATE UNIQUE INDEX Voucher_Id ON Voucher(Id)",
+                "CREATE UNIQUE INDEX Voucher_BatchId_SequenceNumber ON Voucher(BatchId, SequenceNumber)",
+                "CREATE UNIQUE INDEX SessionData_Key ON SessionData(Key)",
+                "CREATE UNIQUE INDEX Parameters_Key ON Parameters(Key)",
+                "CREATE INDEX Orders_OrderDate ON Orders(OrderDate)",
+                "CREATE INDEX OrderedItems_OrderId ON OrderedItems(OrderId)",
+                "UPDATE Parameters SET Value='2' WHERE Key='Migration'",
+                "UPDATE Batch SET Downloaded=(ReadyForDownload=1 AND DeliveredQuantity<=COALESCE((SELECT COUNT(*) FROM Voucher WHERE Voucher.BatchId=Batch.Id), 0))",
+                "INSERT INTO Parameters (Key, Value) VALUES ('LastSyncedBatchId', '0')",
+                "CREATE TABLE Logs_New (" +
+                    "Id INTEGER PRIMARY KEY AUTOINCREMENT," +
+                    "UserId INT NOT NULL," +
+                    "VoucherId INT," +
+                    "EventDate DATETIME," +
+                    "EventType VARCHAR(50)," +
+                    "Retry BOOLEAN)",
+                "INSERT INTO Logs_New (Id, UserId, VoucherId, EventDate, EventType, Retry) " +
+                    "SELECT Id, UserId, VoucherId, EventDate, EventType, Retry FROM Logs",
+                "DROP TABLE Logs",
+                "ALTER TABLE Logs_New RENAME TO Logs"
+            );
         }
     }
 }

BulkPrinting/BulkPrinting/OrderForm.cs

 using System;
 using System.Collections.Generic;
-using System.Collections.ObjectModel;
 using System.ComponentModel;
-using System.Data;
-using System.Drawing;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using System.Windows.Forms;
-using System.IO;
-using System.Net;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Serialization;
+using System.Data.SQLite;
 using System.Runtime.CompilerServices;
 using System.Threading;
-using System.Data.SQLite;
+using System.Windows.Forms;
 
 namespace BulkPrinting
 {
             DialogResult PlaceOrder = MessageBox.Show(OrderReviewMessage, "Proceed?", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
             if (PlaceOrder == DialogResult.Yes) {
                 string InternalReference = Utility.GetNextInternalReference();
-                string Sql = "INSERT INTO Orders (UserId,UserName,OrderDate,OrderCost,BalanceAfterOrder,InternalReference) VALUES (@userid,@username,datetime('now'),@ordercost,@balanceafterorder,@internalreference)";
-                SQLiteCommand Command = new SQLiteCommand(Sql, Globals.DBConnection);
-                Command.Parameters.Add(new SQLiteParameter("@userid", Globals.SessionData.Credentials.Payload.User.Id));
-                Command.Parameters.Add(new SQLiteParameter("@username", Globals.SessionData.Credentials.Payload.User.FirstName + " " + Globals.SessionData.Credentials.Payload.User.Surname));
-                Command.Parameters.Add(new SQLiteParameter("@ordercost", TotalCost));
-                Command.Parameters.Add(new SQLiteParameter("@balanceafterorder", Globals.SessionData.Credentials.Payload.User.Account.Balance - TotalCost));
-                Command.Parameters.Add(new SQLiteParameter("@internalreference", InternalReference));
-                Command.ExecuteNonQuery();
+                Utility.DBExecuteNonQuery(Globals.DBConnection,
+                    "INSERT INTO Orders (UserId,UserName,OrderDate,OrderCost,BalanceAfterOrder,InternalReference) VALUES (@userid,@username,datetime('now'),@ordercost,@balanceafterorder,@internalreference)",
+                        new SQLiteParameter("@userid", Globals.SessionData.Credentials.Payload.User.Id),
+                        new SQLiteParameter("@username", Globals.SessionData.Credentials.Payload.User.FirstName + " " + Globals.SessionData.Credentials.Payload.User.Surname),
+                        new SQLiteParameter("@ordercost", TotalCost),
+                        new SQLiteParameter("@balanceafterorder", Globals.SessionData.Credentials.Payload.User.Account.Balance - TotalCost),
+                        new SQLiteParameter("@internalreference", InternalReference));
 
-                Sql = "SELECT MAX(Id) FROM Orders";
-                Command = new SQLiteCommand(Sql, Globals.DBConnection);
-                int OrderId = int.Parse(Command.ExecuteScalar().ToString()); 
+                int OrderId = int.Parse(Utility.DBExecuteScalar(Globals.DBConnection, "SELECT MAX(Id) FROM Orders").ToString());
 
-                Sql = "INSERT INTO OrderedItems (OrderId,Cost,Quantity,Description,ProductId) VALUES (@orderId,@cost,@quantity,@description,@productid)";
-                for (int i = 0; i < this.SelectedProducts.Count; i++)
+                lock (Globals.DBWriteLock)
                 {
-                    OrderItem OrderedItem = this.SelectedProducts[i];
-                    decimal ItemCost = OrderedItem.Quantity * OrderedItem.FaceValue * (1 - (OrderedItem.DiscountPercentage / 100));
-                    Command = new SQLiteCommand(Sql, Globals.DBConnection);
-                    Command.Parameters.Add(new SQLiteParameter("@orderId", OrderId));
-                    Command.Parameters.Add(new SQLiteParameter("@cost", ItemCost));
-                    Command.Parameters.Add(new SQLiteParameter("@quantity", OrderedItem.Quantity));
-                    Command.Parameters.Add(new SQLiteParameter("@description", OrderedItem.ProductDescription));
-                    Command.Parameters.Add(new SQLiteParameter("@productid", OrderedItem.ProductId));
-                    Command.ExecuteNonQuery();
+                    using (var trans = Globals.DBConnection.BeginTransaction())
+                    {
+                        var Sql = "INSERT INTO OrderedItems (OrderId,Cost,Quantity,Description,ProductId) VALUES (@orderId,@cost,@quantity,@description,@productid)";
+                        using (var Command = new SQLiteCommand(Sql, Globals.DBConnection, trans))
+                        {
+                            for (int i = 0; i < this.SelectedProducts.Count; i++)
+                            {
+                                OrderItem OrderedItem = this.SelectedProducts[i];
+                                decimal ItemCost = OrderedItem.Quantity * OrderedItem.FaceValue * (1 - (OrderedItem.DiscountPercentage / 100));
+                                Command.Parameters.Clear();
+                                Command.Parameters.AddWithValue("@orderId", OrderId);
+                                Command.Parameters.AddWithValue("@cost", ItemCost);
+                                Command.Parameters.AddWithValue("@quantity", OrderedItem.Quantity);
+                                Command.Parameters.AddWithValue("@description", OrderedItem.ProductDescription);
+                                Command.Parameters.AddWithValue("@productid", OrderedItem.ProductId);
+                                Command.ExecuteNonQuery();
+                            }
+                        }
+                        trans.Commit();
+                    }
                 }
 
                 this.Hide();
                 ProgressDialog Progress = new ProgressDialog();
                 Progress.Show();
                 Thread t = new Thread(() => {
-                    Progress.UpdateProgressText("Please wait...");
-                    Progress.UpdateProgressBar(0);
-                    for (int i=0; i<this.SelectedProducts.Count; i++)
+                    var conn = Globals.DBConnection;
+                    //using (var conn = Utility.OpenDBConnection())
                     {
-                        OrderItem OrderedItem = this.SelectedProducts[i];
-                        Progress.UpdateProgressText("Placing order for " + OrderedItem.Quantity.ToString() + " of " + OrderedItem.ProductDescription + "...");
-                        OrderPlacementData OrderData = new OrderPlacementData();
-                        OrderData.ProductId = OrderedItem.ProductId;
-                        OrderData.Quantity = OrderedItem.Quantity;
-                        OrderData.CustomerReference = CustomerReference;
-                        OrderData.InternalReference = InternalReference;
-                        BatchListing OrderedBatch = new BatchListing();
-                        bool OrderResult = Utility.RESTRequest<OrderPlacementData, BatchListing>(OrderData, ref OrderedBatch, "/api/batches/");
-                        if (OrderedBatch.Batch == null) {
-                            string ErrorMessage = "An error occurred while attempting to order " + OrderedItem.Quantity.ToString() + " of " + OrderedItem.ProductDescription;
-                            if (i < (SelectedProducts.Count - 1)){
-                                ErrorMessage += "\nPress OK to continue attempting to order remaining items.";
+                        Progress.UpdateProgressText("Please wait...");
+                        Progress.UpdateProgressBar(0);
+                        for (int i = 0; i < this.SelectedProducts.Count; i++)
+                        {
+                            OrderItem OrderedItem = this.SelectedProducts[i];
+                            Progress.UpdateProgressText("Placing order for " + OrderedItem.Quantity.ToString() + " of " + OrderedItem.ProductDescription + "...");
+                            OrderPlacementData OrderData = new OrderPlacementData();
+                            OrderData.ProductId = OrderedItem.ProductId;
+                            OrderData.Quantity = OrderedItem.Quantity;
+                            OrderData.CustomerReference = CustomerReference;
+                            OrderData.InternalReference = InternalReference;
+                            BatchListing OrderedBatch = new BatchListing();
+                            bool OrderResult = Utility.RESTRequest<OrderPlacementData, BatchListing>(OrderData, ref OrderedBatch, "/api/batches/");
+                            if (OrderedBatch.Batch == null)
+                            {
+                                string ErrorMessage = "An error occurred while attempting to order " + OrderedItem.Quantity.ToString() + " of " + OrderedItem.ProductDescription;
+                                if (i < (SelectedProducts.Count - 1))
+                                {
+                                    ErrorMessage += "\nPress OK to continue attempting to order remaining items.";
+                                }
+                                MessageBox.Show(ErrorMessage, "Error Ordering", MessageBoxButtons.OK, MessageBoxIcon.Error);
+                                continue;
                             }
-                            MessageBox.Show(ErrorMessage ,"Error Ordering",MessageBoxButtons.OK,MessageBoxIcon.Error);
-                            continue;
+                            //TODO: Handle failed order
+                            Utility.SaveBatch(conn, OrderedBatch.Batch);
+                            SourceForm.NewBatchAvailable();
+                            Globals.SessionData.Credentials.Payload.User.Account.Balance = OrderedBatch.RemainingBalance;
+                            Utility.AddUserUsage(conn, UserLimits.UserLimitTypes.BulkOrder, OrderedBatch.Batch.Cost);
+                            Progress.UpdateProgressBar((int)Math.Round(100 * (((decimal)i + 1) / (decimal)SelectedProducts.Count)));
+                            Thread.Sleep(50);
                         }
-                        //TODO: Handle failed order
-                        Utility.DownloadBatch(OrderedBatch.Batch);
-                        Globals.SessionData.Credentials.Payload.User.Account.Balance = OrderedBatch.RemainingBalance;
-                        Utility.AddUserUsage(UserLimits.UserLimitTypes.BulkOrder, OrderedBatch.Batch.Cost);
-                        Progress.UpdateProgressBar((int)Math.Round(100 * (((decimal)i+1)/(decimal)SelectedProducts.Count)));
-                        Thread.Sleep(50);
-                    }
 
-                    Progress.Invoke((Action)(() => Progress.Close()));
-                    this.Invoke((Action)(() => { SourceForm.PopulateGrid(); this.Close(); }));
+                        Progress.Invoke((Action)(() => Progress.Close()));
+                        this.Invoke((Action)(() => { SourceForm.PopulateGrid(); this.Close(); }));
+                    }
                 });
                 t.Start();
             }

BulkPrinting/BulkPrinting/OrderReport.cs

             dgvOrderReport.Columns.Add("DeliveredQuantity", "Delivered Quantity");
             string Sql = "Select o.Id,o.InternalReference,o.UserId,o.UserName,o.OrderDate,oi.Description,o.OrderCost,o.BalanceAfterOrder,oi.Cost,b.RequestedQuantity,b.DeliveredQuantity From Orders o LEFT JOIN OrderedItems oi on oi.OrderId = o.Id LEFT JOIN Batch b ON b.InternalReference = o.InternalReference AND b.ProductId = oi.ProductId WHERE o.OrderDate BETWEEN @startdate AND @enddate";
 
-            SQLiteCommand Command = new SQLiteCommand(Sql, Globals.DBConnection);
-            CultureInfo IVC = CultureInfo.InvariantCulture;
-            Command.Parameters.Add(new SQLiteParameter("@startdate", dtpStartDate.Value.ToString("yyyy-MM-dd 00:00:00", IVC)));
-            Command.Parameters.Add(new SQLiteParameter("@enddate", dtpEndDate.Value.ToString("yyyy-MM-dd 23:59:59", IVC)));
-
-            using (SQLiteDataReader read = Command.ExecuteReader())
+            using (var Command = new SQLiteCommand(Sql, Globals.DBConnection))
             {
-                while (read.Read())
+                CultureInfo IVC = CultureInfo.InvariantCulture;
+                Command.Parameters.AddWithValue("@startdate", dtpStartDate.Value.ToString("yyyy-MM-dd 00:00:00", IVC));
+                Command.Parameters.AddWithValue("@enddate", dtpEndDate.Value.ToString("yyyy-MM-dd 23:59:59", IVC));
+
+                using (SQLiteDataReader read = Command.ExecuteReader())
                 {
-                    dgvOrderReport.Rows.Add(new object[] {
-                    read.GetValue(1).ToString(),
-                    read.GetValue(2).ToString(),
-                    read.GetValue(3).ToString(),
-                    read.GetValue(4).ToString(),
-                    read.GetValue(5).ToString(),
-                    read.GetValue(6).ToString(),
-                    read.GetValue(7).ToString(),
-                    read.GetValue(8).ToString(),
-                    read.GetValue(9).ToString(),
-                    read.GetValue(10).ToString(),
-                });
+                    while (read.Read())
+                    {
+                        dgvOrderReport.Rows.Add(new object[] {
+                            read.GetValue(1).ToString(),
+                            read.GetValue(2).ToString(),
+                            read.GetValue(3).ToString(),
+                            read.GetValue(4).ToString(),
+                            read.GetValue(5).ToString(),
+                            read.GetValue(6).ToString(),
+                            read.GetValue(7).ToString(),
+                            read.GetValue(8).ToString(),
+                            read.GetValue(9).ToString(),
+                            read.GetValue(10).ToString(),
+                        });
+                    }
                 }
             }
-
         }
 
         private void OrderReport_Load(object sender, EventArgs e)
         private void btnPrint_Click(object sender, EventArgs e)
         {
             string Sql = "Select o.Id,o.OrderDate,o.InternalReference,o.UserName,o.OrderCost,o.BalanceAfterOrder,oi.Description,oi.Cost,b.RequestedQuantity,b.DeliveredQuantity From Orders o LEFT JOIN OrderedItems oi on oi.OrderId = o.Id LEFT JOIN Batch b ON b.InternalReference = o.InternalReference AND b.ProductId = oi.ProductId WHERE o.OrderDate BETWEEN @startdate AND @enddate ORDER BY o.Id";
-            SQLiteCommand Command = new SQLiteCommand(Sql, Globals.DBConnection);
-            CultureInfo IVC = CultureInfo.InvariantCulture;
-            Command.Parameters.Add(new SQLiteParameter("@startdate", dtpStartDate.Value.ToString("yyyy-MM-dd 00:00:00", IVC)));
-            Command.Parameters.Add(new SQLiteParameter("@enddate", dtpEndDate.Value.ToString("yyyy-MM-dd 23:59:59", IVC)));
-
-            int CurrentId;
-            int LastId = -1;
-            List<OrderList> Orders = new List<OrderList>();
-            OrderList IndividualOrder = new OrderList();
-            using (SQLiteDataReader read = Command.ExecuteReader())
+            using (var Command = new SQLiteCommand(Sql, Globals.DBConnection))
             {
-                while (read.Read())
+                CultureInfo IVC = CultureInfo.InvariantCulture;
+                Command.Parameters.AddWithValue("@startdate", dtpStartDate.Value.ToString("yyyy-MM-dd 00:00:00", IVC));
+                Command.Parameters.AddWithValue("@enddate", dtpEndDate.Value.ToString("yyyy-MM-dd 23:59:59", IVC));
+
+                int CurrentId;
+                int LastId = -1;
+                List<OrderList> Orders = new List<OrderList>();
+                OrderList IndividualOrder = new OrderList();
+                using (SQLiteDataReader read = Command.ExecuteReader())
                 {
-                    CurrentId = int.Parse(read.GetValue(0).ToString());
-                    if (CurrentId != LastId)
+                    while (read.Read())
                     {
-                        if (IndividualOrder.OrderReference != null)
+                        CurrentId = int.Parse(read.GetValue(0).ToString());
+                        if (CurrentId != LastId)
                         {
-                            Orders.Add(IndividualOrder);
+                            if (IndividualOrder.OrderReference != null)
+                            {
+                                Orders.Add(IndividualOrder);
+                            }
+                            IndividualOrder = new OrderList();
+                            IndividualOrder.OrderLines = new List<OrderReportLine>();
+                            IndividualOrder.OrderDate = read.GetValue(1).ToString();
+                            IndividualOrder.OrderDate = IndividualOrder.OrderDate.Substring(0, IndividualOrder.OrderDate.IndexOf(" "));
+                            IndividualOrder.OrderReference = read.GetValue(2).ToString();
+                            IndividualOrder.User = read.GetValue(3).ToString();
+                            IndividualOrder.OrderCost = read.GetValue(4).ToString();
+                            IndividualOrder.Balance = read.GetValue(5).ToString();
+                            LastId = CurrentId;
                         }
-                        IndividualOrder = new OrderList();
-                        IndividualOrder.OrderLines = new List<OrderReportLine>();
-                        IndividualOrder.OrderDate = read.GetValue(1).ToString();
-                        IndividualOrder.OrderDate = IndividualOrder.OrderDate.Substring(0, IndividualOrder.OrderDate.IndexOf(" "));
-                        IndividualOrder.OrderReference = read.GetValue(2).ToString();
-                        IndividualOrder.User = read.GetValue(3).ToString();
-                        IndividualOrder.OrderCost = read.GetValue(4).ToString();
-                        IndividualOrder.Balance = read.GetValue(5).ToString();
-                        LastId = CurrentId;
+                        OrderReportLine OrderLine = new OrderReportLine();
+                        OrderLine.OrderItem = read.GetValue(6).ToString();
+                        OrderLine.Cost = read.GetValue(7).ToString();
+                        OrderLine.QtyOrdered = read.GetValue(8).ToString();
+                        OrderLine.QtyDelivered = read.GetValue(9).ToString();
+                        IndividualOrder.OrderLines.Add(OrderLine);
+                    }
+                    if (IndividualOrder.OrderReference != null)
+                    {
+                        Orders.Add(IndividualOrder);
                     }
-                    OrderReportLine OrderLine = new OrderReportLine();
-                    OrderLine.OrderItem = read.GetValue(6).ToString();
-                    OrderLine.Cost = read.GetValue(7).ToString();
-                    OrderLine.QtyOrdered = read.GetValue(8).ToString();
-                    OrderLine.QtyDelivered = read.GetValue(9).ToString();
-                    IndividualOrder.OrderLines.Add(OrderLine);
-                }
-                if (IndividualOrder.OrderReference != null)
-                {
-                    Orders.Add(IndividualOrder);
                 }
+                Printer.PrintOrderReport(Orders);
             }
-            Printer.PrintOrderReport(Orders);
         }
 
         private void label1_Click(object sender, EventArgs e)

BulkPrinting/BulkPrinting/PrintAlignmentDialog.cs

             }
             else if (NumVouchers != null)
             {
-                string Sql = "SELECT MIN(v.SequenceNumber) FROM Voucher v " +
-                    "LEFT JOIN Logs l ON v.Id = l.VoucherId AND l.EventType = @eventtype " +
-                    "WHERE v.BatchId = @batchid AND l.id IS NULL";
-                SQLiteCommand Command = new SQLiteCommand(Sql, Globals.DBConnection);
-                Command.Parameters.Add(new SQLiteParameter("@eventtype", VendorEvent.VendorEventType.PrintVoucher));
-                Command.Parameters.Add(new SQLiteParameter("@batchid", BatchID));
-                FirstVoucherSequenceNumber = Convert.ToInt32(Command.ExecuteScalar());
+                FirstVoucherSequenceNumber = Convert.ToInt32(Utility.DBExecuteScalar(Globals.DBConnection,
+                    "SELECT MIN(v.SequenceNumber) FROM Voucher v " +
+                        "LEFT JOIN Logs l ON v.Id = l.VoucherId AND l.EventType = @eventtype " +
+                        "WHERE v.BatchId = @batchid AND l.id IS NULL",
+                    new SQLiteParameter("@eventtype", VendorEvent.VendorEventType.PrintVoucher),
+                    new SQLiteParameter("@batchid", BatchID)));
                 LastVoucherSequenceNumber = FirstVoucherSequenceNumber + (int)NumVouchers - 1;
             }
             else {
             this.Enabled = false;
             Thread t = new Thread(() =>
             {
-                Utility.PrintVouchers(this.BatchID, FirstVoucherSequenceNumber, LastVoucherSequenceNumber);
-                Globals.OpenBatches.Remove(BatchID);
-                this.Invoke((Action)(() => {
-                    BatchForm.PopulateGrid();
-                    this.Enabled = true;
-                    this.Close();
-                }));
+                var conn = Globals.DBConnection;
+                //using (var conn = Utility.OpenDBConnection())
+                {
+                    Utility.PrintVouchers(conn, BatchID, FirstVoucherSequenceNumber, LastVoucherSequenceNumber);
+                    Globals.OpenBatches.Remove(BatchID);
+                    this.Invoke((Action)(() =>
+                    {
+                        BatchForm.PopulateGrid();
+                        this.Enabled = true;
+                        this.Close();
+                    }));
+                }
             });
             t.Start();
 

BulkPrinting/BulkPrinting/PrintForm.cs

                     return;
                 }
             }
-            string Sql = "SELECT FaceValue FROM Batch WHERE Id = @id";
-            SQLiteCommand Command = new SQLiteCommand(Sql, Globals.DBConnection);
-            Command.Parameters.Add(new SQLiteParameter("@id", BatchID));
 
             VoucherCount = numNumVouchers.Value;
-            decimal TotalVoucherValue = VoucherCount * (decimal)Command.ExecuteScalar();
+            decimal TotalVoucherValue = VoucherCount * (decimal)Utility.DBExecuteScalar(Globals.DBConnection,
+                "SELECT FaceValue FROM Batch WHERE Id = @id",
+                new SQLiteParameter("@id", BatchID));
+
             if (Globals.SessionMode == SessionModes.Online)
             {
                 if (!Utility.IsValueWithinRemainingUserLimit(UserLimits.UserLimitTypes.OnlinePrint, TotalVoucherValue))

BulkPrinting/BulkPrinting/Printer.cs

         private static PrintDocument pdoc = null;
         private static List<OrderList> OrderReportList;
         private static int ListLoc = 0;
-        private static int pages = 0;
 
         public static void PrintOrderReport(List<OrderList> OrderPrintList)
         {
             ListLoc = 0;
-            pages = 0;
             OrderReportList = OrderPrintList;
             PrintDialog pd = new PrintDialog();
             pd.UseEXDialog = true; //Required for AMD64 based processors

BulkPrinting/BulkPrinting/Program.cs

 using System;
+using System.IO;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
         static void Main()
         {
             Globals.HDDSerialNumber = Utility.GetHDDSerial();
+            Globals.MaxDBPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), Configuration.MaxDataPathName);
+            Globals.MaxDBFilePath = Path.Combine(Globals.MaxDBPath, Configuration.MaxDBFileName);
             Application.EnableVisualStyles();
             Application.SetCompatibleTextRenderingDefault(false);
             Application.Run(new UserLoginForm());

BulkPrinting/BulkPrinting/ReprintForm.cs

             lblFaceValue.Text = FaceValue;
             lblVoucherType.Text = VoucherTypeName;
             lblNetwork.Text = NetworkName;
-            SQLiteCommand Command = new SQLiteCommand("SELECT MIN(v.SequenceNumber), MAX(v.SequenceNumber) FROM Voucher v LEFT JOIN Logs l ON v.Id = l.VoucherId AND l.EventType = @eventtype WHERE l.VoucherId IS NOT NULL AND v.BatchId=@batchid AND Retry=0", Globals.DBConnection);
-            Command.Parameters.Add(new SQLiteParameter("@batchid", BatchID));
-            Command.Parameters.Add(new SQLiteParameter("@eventtype", VendorEvent.VendorEventType.PrintVoucher));
-            SQLiteDataReader read = Command.ExecuteReader();
-            read.Read();
-            MinSeqNo = int.Parse(read.GetValue(0).ToString());
-            MaxSeqNo = int.Parse(read.GetValue(1).ToString());
+            using (var Command = new SQLiteCommand("SELECT MIN(v.SequenceNumber), MAX(v.SequenceNumber) FROM Voucher v LEFT JOIN Logs l ON v.Id = l.VoucherId AND l.EventType = @eventtype WHERE l.VoucherId IS NOT NULL AND v.BatchId=@batchid AND Retry=0", Globals.DBConnection))
+            {
+                Command.Parameters.AddWithValue("@batchid", BatchID);
+                Command.Parameters.AddWithValue("@eventtype", VendorEvent.VendorEventType.PrintVoucher);
+                using (SQLiteDataReader read = Command.ExecuteReader())
+                {
+                    read.Read();
+                    MinSeqNo = int.Parse(read.GetValue(0).ToString());
+                    MaxSeqNo = int.Parse(read.GetValue(1).ToString());
+                }
+            }
+
             numFirstSeqNum.Minimum = MinSeqNo;
             numFirstSeqNum.Maximum = MaxSeqNo;
             numLastSeqNum.Minimum = MinSeqNo;
         {
             int SelectedRangeStart = 0;
             int SelectedRangeEnd = 0;
-            string Sql;
-            SQLiteCommand Command;
 
             decimal VoucherCount;
 
                 SelectedRangeEnd = (int)numLastSeqNum.Value;
             }
             else if (rdoSerial.Checked) {
-                Sql = "SELECT Count(*) FROM Logs l left join Voucher v on l.VoucherId=v.id WHERE v.Serial=@serialnum and l.EventType=@eventtype and Retry=0";
-                Command = new SQLiteCommand(Sql, Globals.DBConnection);
-                Command.Parameters.Add(new SQLiteParameter("@serialnum", txtSerialNum.Text));
-                Command.Parameters.Add(new SQLiteParameter("@eventtype", VendorEvent.VendorEventType.PrintVoucher));
-                int PrintCount = int.Parse(Command.ExecuteScalar().ToString());
+                int PrintCount = int.Parse(Utility.DBExecuteScalar(Globals.DBConnection,
+                    "SELECT Count(*) FROM Logs l left join Voucher v on l.VoucherId=v.id WHERE v.Serial=@serialnum and l.EventType=@eventtype and Retry=0",
+                    new SQLiteParameter("@serialnum", txtSerialNum.Text),
+                    new SQLiteParameter("@eventtype", VendorEvent.VendorEventType.PrintVoucher)).ToString());
                 if (PrintCount == 0) {
                     MessageBox.Show("No voucher with that serial number was found to have been printed. Please provide a previously printed voucher number or use the 'Print' function to print new vouchers.", "Cannot find printed voucher", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                     return;
                 }
             }
-            Sql = "SELECT FaceValue FROM Batch WHERE Id=@id";
-            Command = new SQLiteCommand(Sql, Globals.DBConnection);
-            Command.Parameters.Add(new SQLiteParameter("@id", BatchID));
 
             VoucherCount = SelectedRangeEnd - SelectedRangeStart + 1;
-            decimal VoucherFaceValue = (decimal)Command.ExecuteScalar();
-
-            string countsql = "SELECT COUNT(v.ID) FROM Voucher v LEFT JOIN Logs l ON v.Id=l.VoucherId AND l.EventType=@event WHERE v.BatchId=@batchid AND v.SequenceNumber BETWEEN @startseq AND @endseq AND l.id IS NULL";
-            SQLiteCommand NewCommand = new SQLiteCommand(countsql, Globals.DBConnection);
+            decimal VoucherFaceValue = (decimal)Utility.DBExecuteScalar(Globals.DBConnection,
+                "SELECT FaceValue FROM Batch WHERE Id=@id",
+                new SQLiteParameter("@id", BatchID));
 
-            NewCommand.Parameters.AddWithValue("@event", (int) VendorEvent.VendorEventType.PrintVoucher);
-            NewCommand.Parameters.AddWithValue("@batchid", BatchID);
-            NewCommand.Parameters.AddWithValue("@startseq", SelectedRangeStart);
-            NewCommand.Parameters.AddWithValue("@endseq", SelectedRangeEnd);
+            int UnprintedVouchersInRange = int.Parse(Utility.DBExecuteScalar(Globals.DBConnection,
+                "SELECT COUNT(v.ID) FROM Voucher v LEFT JOIN Logs l ON v.Id=l.VoucherId AND l.EventType=@event WHERE v.BatchId=@batchid AND v.SequenceNumber BETWEEN @startseq AND @endseq AND l.id IS NULL",
+                new SQLiteParameter("@event", (int) VendorEvent.VendorEventType.PrintVoucher),
+                new SQLiteParameter("@batchid", BatchID),
+                new SQLiteParameter("@startseq", SelectedRangeStart),
+                new SQLiteParameter("@endseq", SelectedRangeEnd)).ToString());
 
-            var result = Command.ExecuteScalar();//Utility.GetNumberOfUnprintedVouchersInRange((int)numFirstSeqNum.Value, (int)numLastSeqNum.Value, BatchID);
-            int UnprintedVouchersInRange = int.Parse(result.ToString());
             decimal PrintedVoucherValue = (VoucherCount - UnprintedVouchersInRange) * VoucherFaceValue;
             decimal UnprintedVoucherValue = UnprintedVouchersInRange * VoucherFaceValue;
 

BulkPrinting/BulkPrinting/UserLoginForm.cs

         private void btnLogin_Click(object sender, EventArgs e)
         {
             bool LoginSuccessful = false;
-            string MaxDBPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), Configuration.MaxDataPathName);
-            string MaxDBFilePath = Path.Combine(MaxDBPath, Configuration.MaxDBFileName);
             LoginData UserLoginData = new LoginData();
             UserLoginData.VendorId = int.Parse(this.txtVendorID.Text);
             UserLoginData.SerialNumber = Globals.HDDSerialNumber;
                     return;
                 }
 
-                if (!File.Exists(MaxDBFilePath))
+                if (!File.Exists(Globals.MaxDBFilePath))
                 {
                     //Shouldn't get here unless the database is deleted or moved
                     MessageBox.Show("A problem has been detected and online initialisation must be performed. You cannot use offline mode until this has been completed.", "Application error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                 }
                 else
                 {
-                    Globals.DBConnection = new SQLiteConnection(String.Format("Data Source={0};", MaxDBFilePath));
-                    Globals.DBConnection.SetPassword(Globals.SessionDatabasePassword);
-                    Globals.DBConnection.Open();
+                    Globals.DBConnection = Utility.OpenDBConnection();
                     //Test login success
                     Globals.SessionMode = SessionModes.Offline;
-                    SQLiteCommand SQLCommand = new SQLiteCommand("SELECT Value FROM SessionData WHERE Key = 'SessionDataJson'", Globals.DBConnection);
-                    Globals.SessionData = JsonConvert.DeserializeObject<OKResponse>(Convert.ToString(SQLCommand.ExecuteScalar()));
+                    Globals.SessionData = JsonConvert.DeserializeObject<OKResponse>(Convert.ToString(Utility.DBExecuteScalar(
+                        Globals.DBConnection, "SELECT Value FROM SessionData WHERE Key = 'SessionDataJson'")));
                     Globals.SessionVoucherKey = Utility.AesDecryptBytes(Globals.SessionData.Credentials.Payload.EncryptedVoucherKey, userKey);
                     DateTime ServerDate = Globals.SessionData.Credentials.Payload.Date;
                     DateTime Today = DateTime.Now;
                         MessageBox.Show("It looks like this user hasn't performed an online login today or since the application started. You must perform an online login at least once during the day to use the offline feature. To use offline mode, please remember not to close the application after each session.", "Cannot perform offline login", MessageBoxButtons.OK, MessageBoxIcon.Error);
                         return;
                     }
-                    Utility.LogEvent(VendorEvent.VendorEventType.OfflineLogin);
+                    Utility.LogEvent(Globals.DBConnection, VendorEvent.VendorEventType.OfflineLogin);
                     LoginSuccessful = true;
                 }
             }
                         Globals.SessionDatabasePassword = Utility.AesDecryptBytes(Globals.SessionEncryptedDatabasePassword, userKey);
                         Globals.SessionVoucherKey = Utility.AesDecryptBytes(Globals.SessionData.Credentials.Payload.EncryptedVoucherKey, userKey);
 
-                        if (!File.Exists(MaxDBFilePath))
+                        if (!File.Exists(Globals.MaxDBFilePath))
                         {
-                            if (!Directory.Exists(MaxDBPath))
+                            if (!Directory.Exists(Globals.MaxDBPath))
                             {
-                                Directory.CreateDirectory(MaxDBPath);
+                                Directory.CreateDirectory(Globals.MaxDBPath);
                             }
-                            SQLiteConnection.CreateFile(MaxDBFilePath);
-                            Migrations.InitialVersion();
+                            SQLiteConnection.CreateFile(Globals.MaxDBFilePath);
+                            Globals.DBConnection = Utility.OpenDBConnection();
+                            Migrations.InitialVersion(Globals.DBConnection);
                         }
                         else
                         {
-                            Globals.DBConnection = new SQLiteConnection(String.Format("Data Source={0};", MaxDBFilePath));
-                            Globals.DBConnection.SetPassword(Globals.SessionDatabasePassword);
-                            Globals.DBConnection.Open();
+                            Globals.DBConnection = Utility.OpenDBConnection();
                         }
-                        Migrations.CheckMigrations();
+                        Migrations.CheckMigrations(Globals.DBConnection);
+                        Utility.CheckLastSyncedLogID(Globals.DBConnection);
                         Utility.TriggerLogSync(); //Perform log sync before any logging happens to ensure synchronicity with server
                     }
                 }
                 Globals.SessionData.Credentials.Payload.User.OnlineReprintValue = 0;
                 Globals.SessionData.Credentials.Payload.User.OfflineReprintValue = 0;
                 */
-                string Sql = "DELETE FROM SessionData"; //Destroy stored session data on login - keep in memory until logout
-                SQLiteCommand Command = new SQLiteCommand(Sql, Globals.DBConnection);
-                Command.ExecuteNonQuery();
+                Utility.DBExecuteNonQuery(Globals.DBConnection, "DELETE FROM SessionData"); //Destroy stored session data on login - keep in memory until logout
                 Globals.MaxPrinter = new Printer();
                 this.txtPassword.Text = "";
                 this.Hide();

BulkPrinting/BulkPrinting/VoucherForm.Designer.cs

             this.dgvVouchers.BackgroundColor = System.Drawing.Color.FromArgb(((int)(((byte)(107)))), ((int)(((byte)(157)))), ((int)(((byte)(233)))));
             this.dgvVouchers.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
             this.dgvVouchers.EditMode = System.Windows.Forms.DataGridViewEditMode.EditProgrammatically;
-            this.dgvVouchers.Location = new System.Drawing.Point(12, 108);
+            this.dgvVouchers.Location = new System.Drawing.Point(16, 133);
+            this.dgvVouchers.Margin = new System.Windows.Forms.Padding(4, 4, 4, 4);
             this.dgvVouchers.MultiSelect = false;
             this.dgvVouchers.Name = "dgvVouchers";
             this.dgvVouchers.SelectionMode = System.Windows.Forms.DataGridViewSelectionMode.FullRowSelect;
-            this.dgvVouchers.Size = new System.Drawing.Size(704, 434);
+            this.dgvVouchers.Size = new System.Drawing.Size(939, 534);
             this.dgvVouchers.TabIndex = 5;
             this.dgvVouchers.CellContentClick += new System.Windows.Forms.DataGridViewCellEventHandler(this.dgvVouchers_CellContentClick);
             // 
             // 
             this.lblBatchDetails.AutoSize = true;
             this.lblBatchDetails.Font = new System.Drawing.Font("Microsoft Sans Serif", 15.75F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
-            this.lblBatchDetails.Location = new System.Drawing.Point(12, 12);
+            this.lblBatchDetails.Location = new System.Drawing.Point(16, 15);
+            this.lblBatchDetails.Margin = new System.Windows.Forms.Padding(4, 0, 4, 0);
             this.lblBatchDetails.Name = "lblBatchDetails";
-            this.lblBatchDetails.Size = new System.Drawing.Size(0, 25);
+            this.lblBatchDetails.Size = new System.Drawing.Size(0, 31);
             this.lblBatchDetails.TabIndex = 7;
             this.lblBatchDetails.Click += new System.EventHandler(this.lblBatchDetails_Click);
             // 
             // 
             this.rdoPrintDate.AutoSize = true;
             this.rdoPrintDate.ForeColor = System.Drawing.Color.White;
-            this.rdoPrintDate.Location = new System.Drawing.Point(12, 40);
+            this.rdoPrintDate.Location = new System.Drawing.Point(16, 49);
+            this.rdoPrintDate.Margin = new System.Windows.Forms.Padding(4, 4, 4, 4);
             this.rdoPrintDate.Name = "rdoPrintDate";
-            this.rdoPrintDate.Size = new System.Drawing.Size(123, 17);
+            this.rdoPrintDate.Size = new System.Drawing.Size(163, 21);
             this.rdoPrintDate.TabIndex = 8;
             this.rdoPrintDate.Text = "Date Printed (range):";
             this.rdoPrintDate.UseVisualStyleBackColor = true;
             // 
             this.rdoVoucherRange.AutoSize = true;
             this.rdoVoucherRange.ForeColor = System.Drawing.Color.White;
-            this.rdoVoucherRange.Location = new System.Drawing.Point(12, 63);
+            this.rdoVoucherRange.Location = new System.Drawing.Point(16, 78);
+            this.rdoVoucherRange.Margin = new System.Windows.Forms.Padding(4, 4, 4, 4);
             this.rdoVoucherRange.Name = "rdoVoucherRange";
-            this.rdoVoucherRange.Size = new System.Drawing.Size(160, 17);
+            this.rdoVoucherRange.Size = new System.Drawing.Size(207, 21);
             this.rdoVoucherRange.TabIndex = 8;
             this.rdoVoucherRange.Text = "Vouchers in Selected Batch:";
             this.rdoVoucherRange.UseVisualStyleBackColor = true;
             this.rdoSerialNum.AutoSize = true;
             this.rdoSerialNum.Checked = true;
             this.rdoSerialNum.ForeColor = System.Drawing.Color.White;
-            this.rdoSerialNum.Location = new System.Drawing.Point(12, 86);
+            this.rdoSerialNum.Location = new System.Drawing.Point(16, 106);
+            this.rdoSerialNum.Margin = new System.Windows.Forms.Padding(4, 4, 4, 4);
             this.rdoSerialNum.Name = "rdoSerialNum";
-            this.rdoSerialNum.Size = new System.Drawing.Size(94, 17);
+            this.rdoSerialNum.Size = new System.Drawing.Size(123, 21);
             this.rdoSerialNum.TabIndex = 8;
             this.rdoSerialNum.TabStop = true;
             this.rdoSerialNum.Text = "Serial Number:";
             // 
             this.label1.AutoSize = true;
             this.label1.ForeColor = System.Drawing.Color.White;
-            this.label1.Location = new System.Drawing.Point(12, 12);
+            this.label1.Location = new System.Drawing.Point(16, 15);
+            this.label1.Margin = new System.Windows.Forms.Padding(4, 0, 4, 0);
             this.label1.Name = "label1";
-            this.label1.Size = new System.Drawing.Size(120, 13);
+            this.label1.Size = new System.Drawing.Size(159, 17);
             this.label1.TabIndex = 9;
             this.label1.Text = "Search for vouchers by:";
             this.label1.Click += new System.EventHandler(this.label1_Click);
             // dtpStartDate
             // 
             this.dtpStartDate.Format = System.Windows.Forms.DateTimePickerFormat.Short;
-            this.dtpStartDate.Location = new System.Drawing.Point(353, 39);
+            this.dtpStartDate.Location = new System.Drawing.Point(471, 48);
+            this.dtpStartDate.Margin = new System.Windows.Forms.Padding(4, 4, 4, 4);
             this.dtpStartDate.Name = "dtpStartDate";
-            this.dtpStartDate.Size = new System.Drawing.Size(100, 20);
+            this.dtpStartDate.Size = new System.Drawing.Size(132, 22);
             this.dtpStartDate.TabIndex = 10;
             this.dtpStartDate.ValueChanged += new System.EventHandler(this.dtpStartDate_ValueChanged);
             // 
             // dtpEndDate
             // 
             this.dtpEndDate.Format = System.Windows.Forms.DateTimePickerFormat.Short;
-            this.dtpEndDate.Location = new System.Drawing.Point(510, 39);
+            this.dtpEndDate.Location = new System.Drawing.Point(680, 48);
+            this.dtpEndDate.Margin = new System.Windows.Forms.Padding(4, 4, 4, 4);
             this.dtpEndDate.Name = "dtpEndDate";
-            this.dtpEndDate.Size = new System.Drawing.Size(100, 20);
+            this.dtpEndDate.Size = new System.Drawing.Size(132, 22);
             this.dtpEndDate.TabIndex = 10;
             this.dtpEndDate.ValueChanged += new System.EventHandler(this.dtpEndDate_ValueChanged);
             // 
             // txtSerial
             // 
-            this.txtSerial.Location = new System.Drawing.Point(320, 85);
+            this.txtSerial.Location = new System.Drawing.Point(427, 105);
+            this.txtSerial.Margin = new System.Windows.Forms.Padding(4, 4, 4, 4);
             this.txtSerial.Name = "txtSerial";
-            this.txtSerial.Size = new System.Drawing.Size(290, 20);
+            this.txtSerial.Size = new System.Drawing.Size(385, 22);
             this.txtSerial.TabIndex = 11;
             // 
             // lblBatch1
             // 
             this.lblBatch1.AutoSize = true;
             this.lblBatch1.ForeColor = System.Drawing.Color.White;
-            this.lblBatch1.Location = new System.Drawing.Point(317, 64);
+            this.lblBatch1.Location = new System.Drawing.Point(423, 79);
+            this.lblBatch1.Margin = new System.Windows.Forms.Padding(4, 0, 4, 0);
             this.lblBatch1.Name = "lblBatch1";
-            this.lblBatch1.Size = new System.Drawing.Size(30, 13);
+            this.lblBatch1.Size = new System.Drawing.Size(40, 17);
             this.lblBatch1.TabIndex = 12;
             this.lblBatch1.Text = "From";
             this.lblBatch1.Click += new System.EventHandler(this.lblBatch1_Click);
             // 
             this.label3.AutoSize = true;
             this.label3.ForeColor = System.Drawing.Color.White;
-            this.label3.Location = new System.Drawing.Point(317, 41);
+            this.label3.Location = new System.Drawing.Point(423, 50);
+            this.label3.Margin = new System.Windows.Forms.Padding(4, 0, 4, 0);
             this.label3.Name = "label3";
-            this.label3.Size = new System.Drawing.Size(30, 13);
+            this.label3.Size = new System.Drawing.Size(40, 17);
             this.label3.TabIndex = 12;
             this.label3.Text = "From";
             this.label3.Click += new System.EventHandler(this.label3_Click);
             // 
             this.label4.AutoSize = true;
             this.label4.ForeColor = System.Drawing.Color.White;
-            this.label4.Location = new System.Drawing.Point(484, 41);
+            this.label4.Location = new System.Drawing.Point(645, 50);
+            this.label4.Margin = new System.Windows.Forms.Padding(4, 0, 4, 0);
             this.label4.Name = "label4";
-            this.label4.Size = new System.Drawing.Size(20, 13);
+            this.label4.Size = new System.Drawing.Size(25, 17);
             this.label4.TabIndex = 12;
             this.label4.Text = "To";
             this.label4.Click += new System.EventHandler(this.label4_Click);
             // 
             this.lblBatch2.AutoSize = true;
             this.lblBatch2.ForeColor = System.Drawing.Color.White;
-            this.lblBatch2.Location = new System.Drawing.Point(484, 64);
+            this.lblBatch2.Location = new System.Drawing.Point(645, 79);
+            this.lblBatch2.Margin = new System.Windows.Forms.Padding(4, 0, 4, 0);
             this.lblBatch2.Name = "lblBatch2";
-            this.lblBatch2.Size = new System.Drawing.Size(20, 13);
+            this.lblBatch2.Size = new System.Drawing.Size(25, 17);
             this.lblBatch2.TabIndex = 12;
             this.lblBatch2.Text = "To";
             this.lblBatch2.Click += new System.EventHandler(this.lblBatch2_Click);
             // 
             // numStartSeqNo
             // 
-            this.numStartSeqNo.Location = new System.Drawing.Point(353, 62);
+            this.numStartSeqNo.Location = new System.Drawing.Point(471, 76);
+            this.numStartSeqNo.Margin = new System.Windows.Forms.Padding(4, 4, 4, 4);
             this.numStartSeqNo.Name = "numStartSeqNo";
-            this.numStartSeqNo.Size = new System.Drawing.Size(100, 20);
+            this.numStartSeqNo.Size = new System.Drawing.Size(133, 22);
             this.numStartSeqNo.TabIndex = 14;
             this.numStartSeqNo.ValueChanged += new System.EventHandler(this.numStartSeqNo_ValueChanged);
             // 
             // numEndSeqNo
             // 
-            this.numEndSeqNo.Location = new System.Drawing.Point(510, 62);
+            this.numEndSeqNo.Location = new System.Drawing.Point(680, 76);
+            this.numEndSeqNo.Margin = new System.Windows.Forms.Padding(4, 4, 4, 4);
             this.numEndSeqNo.Name = "numEndSeqNo";
-            this.numEndSeqNo.Size = new System.Drawing.Size(100, 20);
+            this.numEndSeqNo.Size = new System.Drawing.Size(133, 22);
             this.numEndSeqNo.TabIndex = 14;
             this.numEndSeqNo.ValueChanged += new System.EventHandler(this.numEndSeqNo_ValueChanged);
             // 
             // 
             this.btnSearch.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(100)))), ((int)(((byte)(132)))), ((int)(((byte)(186)))));
             this.btnSearch.BackgroundImage = ((System.Drawing.Image)(resources.GetObject("btnSearch.BackgroundImage")));
+            this.btnSearch.BackgroundImageLayout = System.Windows.Forms.ImageLayout.Center;
             this.btnSearch.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
-            this.btnSearch.Location = new System.Drawing.Point(616, 2);
+            this.btnSearch.Location = new System.Drawing.Point(821, 2);
+            this.btnSearch.Margin = new System.Windows.Forms.Padding(4, 4, 4, 4);
             this.btnSearch.Name = "btnSearch";
-            this.btnSearch.Size = new System.Drawing.Size(100, 100);
+            this.btnSearch.Size = new System.Drawing.Size(133, 123);
             this.btnSearch.TabIndex = 13;
             this.btnSearch.UseVisualStyleBackColor = false;
             this.btnSearch.Click += new System.EventHandler(this.btnSearch_Click);
             // 
             // numBatchId
             // 
-            this.numBatchId.Location = new System.Drawing.Point(242, 62);
+            this.numBatchId.Location = new System.Drawing.Point(323, 76);
+            this.numBatchId.Margin = new System.Windows.Forms.Padding(4, 4, 4, 4);
             this.numBatchId.Name = "numBatchId";
-            this.numBatchId.Size = new System.Drawing.Size(69, 20);
+            this.numBatchId.Size = new System.Drawing.Size(92, 22);
             this.numBatchId.TabIndex = 15;
             // 
             // label2
             // 
             this.label2.AutoSize = true;
             this.label2.ForeColor = System.Drawing.Color.White;
-            this.label2.Location = new System.Drawing.Point(187, 65);
+            this.label2.Location = new System.Drawing.Point(249, 80);
+            this.label2.Margin = new System.Windows.Forms.Padding(4, 0, 4, 0);
             this.label2.Name = "label2";
-            this.label2.Size = new System.Drawing.Size(49, 13);
+            this.label2.Size = new System.Drawing.Size(61, 17);
             this.label2.TabIndex = 16;
             this.label2.Text = "Batch ID";
             // 
             // VoucherForm
             // 
-            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
+            this.AutoScaleDimensions = new System.Drawing.SizeF(8F, 16F);
             this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
             this.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(7)))), ((int)(((byte)(63)))), ((int)(((byte)(145)))));
-            this.ClientSize = new System.Drawing.Size(728, 554);
+            this.ClientSize = new System.Drawing.Size(971, 682);
             this.Controls.Add(this.label2);
             this.Controls.Add(this.numBatchId);
             this.Controls.Add(this.numEndSeqNo);
             this.Controls.Add(this.lblBatchDetails);
             this.Controls.Add(this.dgvVouchers);
             this.Icon = ((System.Drawing.Icon)(resources.GetObject("$this.Icon")));
-            this.MinimumSize = new System.Drawing.Size(621, 531);
+            this.Margin = new System.Windows.Forms.Padding(4, 4, 4, 4);
+            this.MinimumSize = new System.Drawing.Size(822, 643);
             this.Name = "VoucherForm";
             this.Text = "View PINs";
             this.Load += new System.EventHandler(this.VoucherForm_Load);

BulkPrinting/BulkPrinting/VoucherForm.cs

 
         private void btnSearch_Click(object sender, EventArgs e)
         {
-            string Sql;
-            SQLiteCommand Command = new SQLiteCommand();
-            if (rdoPrintDate.Checked) {
-                Sql = "SELECT v.BatchId, v.Serial, v.SequenceNumber, v.ExpiryDate, v.EncryptedPIN FROM Voucher v LEFT JOIN Logs l on v.Id = l.VoucherId and l.EventType=@eventtype WHERE l.EventDate BETWEEN @startdate AND @enddate";
-                Command = new SQLiteCommand(Sql, Globals.DBConnection);
-                Command.Parameters.Add(new SQLiteParameter("@eventtype", VendorEvent.VendorEventType.PrintVoucher));
-                CultureInfo IVC = CultureInfo.InvariantCulture;
-                Command.Parameters.Add(new SQLiteParameter("@startdate", dtpStartDate.Value.ToString("yyyy-MM-dd 00:00:00", IVC)));
-                Command.Parameters.Add(new SQLiteParameter("@enddate", dtpEndDate.Value.ToString("yyyy-MM-dd 23:59:59", IVC)));
-            }
-            else if (rdoVoucherRange.Checked) {
-                Sql = "SELECT BatchId, Serial, SequenceNumber, ExpiryDate, EncryptedPIN FROM Voucher WHERE BatchId = @batchid AND SequenceNumber BETWEEN @minseqno AND @maxseqno";
-                Command = new SQLiteCommand(Sql, Globals.DBConnection);
-                Command.Parameters.Add(new SQLiteParameter("@batchid", numBatchId.Value));
-                Command.Parameters.Add(new SQLiteParameter("@minseqno", numStartSeqNo.Value));
-                Command.Parameters.Add(new SQLiteParameter("@maxseqno", numEndSeqNo.Value));
-            }
-            else if (rdoSerialNum.Checked) {
-                Sql = "SELECT BatchId, Serial, SequenceNumber, ExpiryDate, EncryptedPIN FROM Voucher WHERE Serial=@serial";
-                Command = new SQLiteCommand(Sql, Globals.DBConnection);
-                Command.Parameters.Add(new SQLiteParameter("@serial", txtSerial.Text));
-            }
-
-            dgvVouchers.Rows.Clear();
-            dgvVouchers.Columns.Clear();
-            dgvVouchers.Columns.Add("BatchId", "Batch ID");
-            dgvVouchers.Columns.Add("Serial", "Serial Number");
-            dgvVouchers.Columns.Add("SequenceNumber", "Sequence Number");
-            dgvVouchers.Columns.Add("ExpiryDate", "Expiry Date");
-            dgvVouchers.Columns.Add("PIN", "PIN");
-            using (SQLiteDataReader SQLReader = Command.ExecuteReader())
+            using (var Command = new SQLiteCommand(Globals.DBConnection))
             {
-                while (SQLReader.Read())
+                if (rdoPrintDate.Checked)
+                {
+                    Command.CommandText = "SELECT v.BatchId, v.Serial, v.SequenceNumber, v.ExpiryDate, v.EncryptedPIN FROM Voucher v LEFT JOIN Logs l on v.Id = l.VoucherId and l.EventType=@eventtype WHERE l.EventDate BETWEEN @startdate AND @enddate";
+                    Command.Parameters.AddWithValue("@eventtype", VendorEvent.VendorEventType.PrintVoucher);
+                    CultureInfo IVC = CultureInfo.InvariantCulture;
+                    Command.Parameters.AddWithValue("@startdate", dtpStartDate.Value.ToString("yyyy-MM-dd 00:00:00", IVC));
+                    Command.Parameters.AddWithValue("@enddate", dtpEndDate.Value.ToString("yyyy-MM-dd 23:59:59", IVC));
+                }
+                else if (rdoVoucherRange.Checked)
+                {
+                    Command.CommandText = "SELECT BatchId, Serial, SequenceNumber, ExpiryDate, EncryptedPIN FROM Voucher WHERE BatchId = @batchid AND SequenceNumber BETWEEN @minseqno AND @maxseqno";
+                    Command.Parameters.AddWithValue("@batchid", numBatchId.Value);
+                    Command.Parameters.AddWithValue("@minseqno", numStartSeqNo.Value);
+                    Command.Parameters.AddWithValue("@maxseqno", numEndSeqNo.Value);
+                }
+                else if (rdoSerialNum.Checked)
+                {
+                    Command.CommandText = "SELECT BatchId, Serial, SequenceNumber, ExpiryDate, EncryptedPIN FROM Voucher WHERE Serial=@serial";
+                    Command.Parameters.AddWithValue("@serial", txtSerial.Text);
+                }
+
+                dgvVouchers.Rows.Clear();
+                dgvVouchers.Columns.Clear();
+                dgvVouchers.Columns.Add("BatchId", "Batch ID");
+                dgvVouchers.Columns.Add("Serial", "Serial Number");
+                dgvVouchers.Columns.Add("SequenceNumber", "Sequence Number");
+                dgvVouchers.Columns.Add("ExpiryDate", "Expiry Date");
+                dgvVouchers.Columns.Add("PIN", "PIN");
+                using (SQLiteDataReader SQLReader = Command.ExecuteReader())
                 {
-                    string VoucherPIN = Utility.TripleDESDecrypt(SQLReader.GetValue(4).ToString(), Globals.SessionVoucherKey).ToString();
-                    dgvVouchers.Rows.Add(new object[] {
-                        SQLReader.GetValue(0),
-                        SQLReader.GetValue(1),
-                        SQLReader.GetValue(2),
-                        SQLReader.GetValue(3),
-                        VoucherPIN
-                    });
+                    while (SQLReader.Read())
+                    {
+                        string VoucherPIN = Utility.TripleDESDecrypt(SQLReader.GetValue(4).ToString(), Globals.SessionVoucherKey).ToString();
+                        dgvVouchers.Rows.Add(new object[] {
+                            SQLReader.GetValue(0),
+                            SQLReader.GetValue(1),
+                            SQLReader.GetValue(2),
+                            SQLReader.GetValue(3),
+                            VoucherPIN
+                        });
+                    }
                 }
             }
         }