Hello friends. In this article I will tell you how you can retrieve database column value in the combo box of C# Windows desktop applications. So let's start .

Step 1
Open your Visual Studio and create a new project from File Menu > New > Project
Save Image In Row Format / Bytes Into Database And Fetch From Database In C# Windows Desktop Application
Step 2
Select Windows desktop app from menu:
Save Image In Row Format / Bytes Into Database And Fetch From Database In C# Windows Desktop Application
Step 3
Enter your project name and path of your location where you want to save your project.
Save Image In Row Format / Bytes Into Database And Fetch From Database In C# Windows Desktop Application
Step 4
Create design as you want. As you see in the below image here I only added label and a combo box which is empty.
Save Image In Row Format / Bytes Into Database And Fetch From Database In C# Windows Desktop Application
Step 5
Now add database file. Click on your project name from Solution Explorer Add > New file or you can simply use short cut key Ctrl+Shift+A
Save Image In Row Format / Bytes Into Database And Fetch From Database In C# Windows Desktop Application
Step 6
Select service based database. Give name as you want and click on add.
Save Image In Row Format / Bytes Into Database And Fetch From Database In C# Windows Desktop Application
Step 7
Now create a new table. Double click on your database file; it will open Server Explorer. Then right click on Table > Add New Table . As you see in the below image our table has only two columns, Id And Name .
Save Image In Row Format / Bytes Into Database And Fetch From Database In C# Windows Desktop Application
Here is the data of our table,
Save Image In Row Format / Bytes Into Database And Fetch From Database In C# Windows Desktop Application
Step 8
Now copy your connection string by right clicking on Database Name > Modify Connection > Advance .
Save Image In Row Format / Bytes Into Database And Fetch From Database In C# Windows Desktop Application
Step 9
Now add new SQL Connection on your form load event as shown in the below image .
Save Image In Row Format / Bytes Into Database And Fetch From Database In C# Windows Desktop Application
Step 10
Here I created a separate function for getting data from database and bound it in combo box and I called that function in form load event. You can also write that code directly on form load event.
Save Image In Row Format / Bytes Into Database And Fetch From Database In C# Windows Desktop Application
Step 11
Now run your application. As you can see that combo box gets all the names from the database.
Save Image In Row Format / Bytes Into Database And Fetch From Database In C# Windows Desktop Application
Below is the full source code of this project,
  1. using System;
  2. using System.Collections.Generic;
  3. using System.ComponentModel;
  4. using System.Data;
  5. using System.Drawing;
  6. using System.Linq;
  7. using System.Text;
  8. using System.Threading.Tasks;
  9. using System.Windows.Forms;
  10. using System.Data.SqlClient;
  11. namespace SaveAndDisplayImageFromDatabase
  12. {
  13. public partial class BindComboBox : Form
  14. {
  15. public BindComboBox()
  16. {
  17. InitializeComponent();
  18. }
  19. SqlConnection cn;
  20. SqlCommand cmd;
  21. SqlDataReader dr;
  22. private void BindComboBox_Load(object sender, EventArgs e)
  23. {
  24. cn = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=G:\Tutorial\SaveAndDisplayImageFromDatabase\SaveAndDisplayImageFromDatabase\Database1.mdf;Integrated Security=True");
  25. cn.Open();
  26. BindData();
  27. }
  28. public void BindData()
  29. {
  30. cmd = new SqlCommand("select name from Table1", cn);
  31. dr = cmd.ExecuteReader();
  32. while(dr.Read())
  33. {
  34. comboBox1.Items.Add(dr[0].ToString());
  35. }
  36. dr.Close();
  37. }
  38. }
  39. }
I hope you find this article helpful. If you learned anything from this article kindly share with your friends. Thank you.