How select table from database with combobox?

Question

I make wpf database app and I want to select table from my database with combobox.

I have a database with ten tables. I can connect to the database and I can select/updata/insert... items from a table. I need to switched between tables. For examp, if I click to Table1, Table1 will selected, if I click to Table2, Table2 will selected. Combobox is good for my app, I believe. This is my code for select:

public MainWindow()
        {
            InitializeComponent();
            loadData();
        }

        public void loadData()
        {
            // vytvoření spojení
            MySqlConnection con = new MySqlConnection(spojeni);
            con.Open();

            MySqlCommand vybrat = con.CreateCommand();     
            vybrat.CommandText = "SELECT * FROM barva";        
            MySqlDataAdapter adapt = new MySqlDataAdapter(vybrat);        
            DataSet data = new DataSet();

            adapt.Fill(data);           
            dtGrid.ItemsSource = data.Tables[0].DefaultView;
          }

PS. I apologize for my English

Create a public list of the table names in your C#, and another public string for the Selected Item, bind a combo box to them, and use that in the SQL. — Robin Bennett, May 20 '19 at 12:56
I know I have to do something like that, but I don't know how. I'm a really bad programmer. This is my combobox: konzole výrobce platforma — ZlyVlk, May 21 '19 at 06:51
Here's an example of how to bind a combobox to a list: https://stackoverflow.com/questions/21898022/wpf-combobox-binding-with-liststring — Robin Bennett, May 21 '19 at 07:59
I read the examples but I still don't understand. If I send you a link to my project, can you explain it to me, please? — ZlyVlk, May 21 '19 at 13:54

score 0 · Answer 1 · answered May 20 '19 at 13:18

I guess you're looking for something like this (connection string belongs under configuration on web.config):

<connectionStrings>
  <add name="YOUR CONNECTION" connectionString="Data Source= ;Initial Catalog= ; User ID= ;Password= ;" providerName="System.Data.SqlClient" />
</connectionStrings>

//Connection to Web.config connectionStrings
DataTable database = new DataTable();
string dbString = ConfigurationManager.ConnectionStrings["YOUR CONNECTION"].ConnectionString;
using (SqlConnection con = new SqlConnection(dbString))
{
    try
    {
        //SQL query
        SqlDataAdapter adapter = new SqlDataAdapter("SELECT * FROM sys.tables", con);
        adapter.Fill(database);

        //Populate ddlTable DropDownList
        ddlTable.DataSource = database;
        ddlTable.DataTextField = "name";
        ddlTable.DataValueField = "name";
        ddlTable.DataBind();
        ddlTable.Items.Insert(0, new ListItem("-- Select Table --", "0"));
    }
    catch (Exception)
    {

    }
}

score 0 · Accepted Answer · answered May 21 '19 at 15:50

Here's a really simple example of binding a combobox to a list of strings, and using the selected string when a button is pressed.

This is the C# code-behind file:

using System.Collections.Generic;
using System.Windows;

namespace WpfCombobox
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            this.InitializeComponent();
        }

        public string MySimpleStringProperty { get; set; }

        public List<string> MyListProperty { get; set; } = new List<string>() { "one", "two", "three" };

        private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
        {
            MessageBox.Show($"Item is {this.MySimpleStringProperty}");
        }
    }
}

Obviously, instead of just displaying the selected item in a message box, you'd use it in your SQL.

And here's the WPF:

<Window x:Class="WpfCombobox.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfCombobox"
        mc:Ignorable="d"
        DataContext="{Binding RelativeSource={RelativeSource Self}}"
        Title="MainWindow" Height="350" Width="525">
    <StackPanel>
        <ComboBox ItemsSource="{Binding MyListProperty}" 
                  SelectedItem="{Binding MySimpleStringProperty}" 
                  IsSynchronizedWithCurrentItem="True" 
                  Text="Select Option"
                  Margin="5"/>
        <Button Click="ButtonBase_OnClick" Content="Click Me!" Margin="5" />
    </StackPanel>
</Window>

Notice that the combobox has an ItemSource, which is bound to the list of strings one, two, three, and a SelectedItem, which changes when the user picks an item.

It works great, thank you. I have the last question: How can I create a dynamic TextBox? I tried something, but it didn't work correct. — ZlyVlk, May 22 '19 at 13:54
What do you mean by 'dynamic'? Do you want to create a control at run-time, rather than code It in the XAML? This example might help: https://stackoverflow.com/questions/12468658/programmatically-add-control-to-grid-rowdefition-in-wpf-4-5 Otherwise, you should ask a new question. — Robin Bennett, May 23 '19 at 07:59
Yes, I mean something like this, but it don't work form me. I'll try to ask a new question. Thank you again for your help. — ZlyVlk, May 23 '19 at 11:12

How select table from database with combobox?

2 Answers2