QueryWindow: Allow users to export query result to csv file

Elwig/Helpers/Export/Csv.cs

@@ -15,7 +15,9 @@ namespace Elwig.Helpers.Export {
         protected readonly char Separator;
         protected string? Header;
 
-        public Csv(string filename, char separator = ';') : this(filename, separator, Utils.UTF8) { }
+        public Csv(string filename, char separator = ';') :
+            this(filename, separator, Utils.UTF8) {
+        }
 
         public Csv(string filename, char separator, Encoding encoding) {
             _writer = new StreamWriter(filename, false, encoding);
@@ -58,4 +60,22 @@ namespace Elwig.Helpers.Export {
 
         public abstract string FormatRow(T row);
     }
+
+    public class CsvSimple : Csv<IEnumerable<object?>> {
+
+        public CsvSimple(string filename, char separator, Encoding encoding) :
+            base(filename, separator, encoding) {
+        }
+
+        public CsvSimple(string filename, char separator = ';') :
+            base(filename, separator) {
+        }
+
+        public override string FormatRow(IEnumerable<object?> row) {
+            return string.Join(Separator, row.Select(i => {
+                var str = $"{i}";
+                return str.Contains(Separator) || str.Contains('\n') ? $"\"{str.Replace("\"", "\"\"")}\"" : str;
+            }));
+        }
+    }
 }

Elwig/Helpers/Utils.cs

@@ -36,6 +36,7 @@ namespace Elwig.Helpers {
     public static partial class Utils {
 
         public static readonly Encoding UTF8 = new UTF8Encoding(false, true);
+        public static readonly Encoding UTF8BOM = new UTF8Encoding(true, true);
         public static readonly JsonSerializerOptions JsonOpts = new() { Encoder = System.Text.Encodings.Web.JavaScriptEncoder.UnsafeRelaxedJsonEscaping };
 
         public static int CurrentYear => DateTime.Now.Year;

Elwig/Windows/QueryWindow.xaml

@@ -5,27 +5,35 @@
         Title="Datenbankabfragen - Elwig" Height="450" Width="800" MinWidth="400" MinHeight="300">
     <Grid>
         <Grid.RowDefinitions>
-            <RowDefinition Height="1*" MinHeight="100"/>
             <RowDefinition Height="5"/>
-            <RowDefinition Height="3*" MinHeight="100"/>
+            <RowDefinition Height="1*" MinHeight="50"/>
+            <RowDefinition Height="5"/>
+            <RowDefinition Height="1*" MinHeight="50"/>
+            <RowDefinition Height="5"/>
+            <RowDefinition Height="6*" MinHeight="100"/>
         </Grid.RowDefinitions>
 
-        <TextBox x:Name="QueryInput" Text="SELECT * FROM v_delivery"
+        <TextBox x:Name="QueryInput" Text="SELECT * FROM v_member" Grid.Row="1" Grid.RowSpan="3"
                  AcceptsReturn="True" VerticalScrollBarVisibility="Visible" TextWrapping="Wrap"
-                 HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Margin="10,10,120,5"
+                 HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Margin="10,5,120,5"
                  FontFamily="Cascadia Code Light" FontSize="13">
             <TextBox.InputBindings>
                 <KeyBinding Key="Return" Modifiers="Control" Command="{Binding EnterCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type local:QueryWindow}}}" />
+                <KeyBinding Key="S" Modifiers="Control" Command="{Binding SaveCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type local:QueryWindow}}}" />
             </TextBox.InputBindings>
         </TextBox>
-        <Button x:Name="QueryButton" Content="Abfragen"
+        <Button x:Name="QueryButton" Content="Abfragen" Grid.Row="1"
-                HorizontalAlignment="Right" VerticalAlignment="Stretch" Margin="10,10,10,5"
+                HorizontalAlignment="Right" VerticalAlignment="Stretch" Margin="10,5,10,0"
                 Click="QueryButton_Click" Width="100"
                 FontSize="14"/>
+        <Button x:Name="SaveButton" Content="Speichern" Grid.Row="3"
+                HorizontalAlignment="Right" VerticalAlignment="Stretch" Margin="10,0,10,5"
+                Click="SaveButton_Click" Width="100"
+                FontSize="14"/>
 
-        <GridSplitter Grid.Row="1" HorizontalAlignment="Stretch" VerticalAlignment="Stretch"/>
+        <GridSplitter Grid.Row="4" HorizontalAlignment="Stretch" VerticalAlignment="Stretch"/>
 
-        <DataGrid x:Name="DataList" Grid.Row="2"
+        <DataGrid x:Name="DataList" Grid.Row="5"
                   AutoGenerateColumns="False" HeadersVisibility="Column" IsReadOnly="True" GridLinesVisibility="None" SelectionMode="Extended"
                   CanUserDeleteRows="False" CanUserResizeRows="False" CanUserAddRows="False"
                   HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Margin="10,5,10,10"/>

Elwig/Windows/QueryWindow.xaml.cs

@@ -1,7 +1,10 @@
 using Elwig.Helpers;
+using Elwig.Helpers.Export;
+using Microsoft.Win32;
 using System;
 using System.Collections.Generic;
 using System.Data.Common;
+using System.Linq;
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Controls;
@@ -13,7 +16,12 @@ namespace Elwig.Windows {
 
         private ICommand? _enterCommand;
         public ICommand EnterCommand => _enterCommand ??= new ActionCommand(async () => {
-            await ExecuteQuery();
+            await DisplayQuery();
+        });
+
+        private ICommand? _saveCommand;
+        public ICommand SaveCommand => _saveCommand ??= new ActionCommand(async () => {
+            await SaveQuery();
         });
 
 
@@ -22,33 +30,45 @@ namespace Elwig.Windows {
         }
 
         private async void QueryButton_Click(object sender, RoutedEventArgs evt) {
-            await ExecuteQuery();
+            await DisplayQuery();
         }
 
-        private async Task ExecuteQuery() {
+        private async void SaveButton_Click(object sender, RoutedEventArgs evt) {
+            await SaveQuery();
+        }
+
+        private async Task DisplayQuery() {
             try {
-                await ExecuteQuery(QueryInput.Text);
+                Mouse.OverrideCursor = Cursors.Wait;
+                await DisplayQuery(QueryInput.Text);
+                Mouse.OverrideCursor = null;
             } catch (Exception e) {
+                Mouse.OverrideCursor = null;
                 MessageBox.Show(e.Message, "Fehler beim Ausführen", MessageBoxButton.OK, MessageBoxImage.Error);
             }
         }
 
-        private async Task ExecuteQuery(string sqlQuery) {
+        private async Task SaveQuery() {
-            var rows = new List<object[]>();
+            await SaveQuery(QueryInput.Text);
-            IList<DbColumn> header;
+        }
 
-            using (var cnx = await AppDbContext.ConnectAsync()) {
+        private static async Task<(IList<DbColumn>, IEnumerable<object[]>)> ExecuteQuery(string sqlQuery) {
+            var rows = new List<object[]>();
+            using var cnx = await AppDbContext.ConnectAsync();
             using var cmd = cnx.CreateCommand();
             cmd.CommandText = sqlQuery;
             using var reader = await cmd.ExecuteReaderAsync();
-                header = await reader.GetColumnSchemaAsync();
+            var header = await reader.GetColumnSchemaAsync();
             while (await reader.ReadAsync()) {
                 var values = new object[reader.FieldCount];
                 reader.GetValues(values);
                 rows.Add(values);
             }
+            return (header, rows);
         }
 
+        private async Task DisplayQuery(string sqlQuery) {
+            var (header, rows) = await ExecuteQuery(sqlQuery);
             var styleRight = new Style();
             styleRight.Setters.Add(new Setter(TextBlock.TextAlignmentProperty, TextAlignment.Right));
 
@@ -63,5 +83,27 @@ namespace Elwig.Windows {
             }
             DataList.ItemsSource = rows;
         }
+
+        private static async Task SaveQuery(string sqlQuery) {
+            var d = new SaveFileDialog() {
+                FileName = $"Abfrage.csv",
+                DefaultExt = "csv",
+                Filter = "CSV-Datei (*.csv)|*.csv",
+                Title = $"Datenbank Abfrage speichern unter - Elwig"
+            };
+            if (d.ShowDialog() == true) {
+                Mouse.OverrideCursor = Cursors.Wait;
+                await Task.Run(async () => {
+                    try {
+                        var (header, rows) = await ExecuteQuery(sqlQuery);
+                        using var csv = new CsvSimple(d.FileName, ';', Utils.UTF8BOM);
+                        await csv.ExportAsync(rows.Prepend([.. header.Select(h => h.ColumnName)]));
+                    } catch (Exception exc) {
+                        MessageBox.Show(exc.Message, "Fehler beim Ausführen", MessageBoxButton.OK, MessageBoxImage.Error);
+                    }
+                });
+                Mouse.OverrideCursor = null;
+            }
+        }
     }
 }