Fill ComboBox from SQL Server in C#

In this article, I will discuss on filling ComboBox values retrieving from SQL Server Database. I'm using my test Database for retrieving data.



 

Create a new project and add a ComboBox to the Form.

 

Add the following code to the Form1.cs class.

 

using System;

using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace FillComboBox
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            fillComboBoxFromSQLServerDB();
        }
        private void fillComboBoxFromSQLServerDB() {
           string connectionString = "Server=localhost\\sqlexpress;Database=test;User Id=sa;Password=abc123;";

            SqlConnection connection = new SqlConnection(connectionString);
            String query = @"Select * From student;";

            SqlCommand command = new SqlCommand(query, connection);
            connection.Open();
            SqlDataReader sqlReader = command.ExecuteReader();
            try
            {
                while (sqlReader.Read())
                {
                    comboBox1.Items.Add(sqlReader[1]);
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show("An error occurred: " + ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            finally
            {
                sqlReader.Close();
            }
            connection.Close();
        }

        } 
    }

Check the output by running the project.

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