Fill ComboBox From Access Database using C# Windows Form Application

In this example, we’ll learn How to fill/populate ComboBox with Access DB Data.

The listbox will populated from database table using OleDbDataReader.

Step 1: We will use the Category table in Customers .accdb database.

Step 2: We should to put the Customers.accdb file in bin/Debug folder.

Step 3: In the next step, create a ComboBox control at design-time, you simply drag and drop a ComboBox control from Toolbox to a Form in Visual Studio.

Step 4: Write a Namespace for connectivity as in the following code snippet.


using System.Data.OleDb;

using System.Data.OleDb;

Step 5: Define global variables.


OleDbConnection con;
OleDbCommand cmd;
OleDbDataReader dr;

OleDbConnection con;

OleDbCommand cmd;

OleDbDataReader dr;

Step 6: Create source code for Form_Load.


private void Form1_Load(object sender, EventArgs e)
        {
            this.Text = "csharp-console-examples.com";
            this.BackColor = Color.YellowGreen;

            con = new OleDbConnection("Provider=Microsoft.ACE.Oledb.12.0;Data Source=Customers.accdb");
            cmd = new OleDbCommand();
            con.Open();
            cmd.Connection = con;
            cmd.CommandText = "SELECT * FROM Category";
            dr = cmd.ExecuteReader();

            while (dr.Read())
            {
                comboBox1.Items.Add(dr["CategoryName"]);
            }
            con.Close();

        }

private void Form1_Load(object sender, EventArgs e)

{

this.Text = "csharp-console-examples.com";

this.BackColor = Color.YellowGreen;

con = new OleDbConnection("Provider=Microsoft.ACE.Oledb.12.0;Data Source=Customers.accdb");

cmd = new OleDbCommand();

con.Open();

cmd.Connection = con;

cmd.CommandText = "SELECT * FROM Category";

dr = cmd.ExecuteReader();

while (dr.Read())

{

comboBox1.Items.Add(dr["CategoryName"]);

}

con.Close();

}

Here are the all codes:


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.Data.OleDb;
namespace fill_combobox_from_access
{
    
    public partial class Form1 : Form
    {
        OleDbConnection con;
        OleDbCommand cmd;
        OleDbDataReader dr;
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            this.Text = "csharp-console-examples.com";
            this.BackColor = Color.YellowGreen;

            con = new OleDbConnection("Provider=Microsoft.ACE.Oledb.12.0;Data Source=Customers.accdb");
            cmd = new OleDbCommand();
            con.Open();
            cmd.Connection = con;
            cmd.CommandText = "SELECT * FROM Category";
            dr = cmd.ExecuteReader();

            while (dr.Read())
            {
                comboBox1.Items.Add(dr["CategoryName"]);
            }
            con.Close();

        }
    }
}

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.Data.OleDb;

namespace fill_combobox_from_access

{

public partial class Form1 : Form

{