C# : Filling Data in the Datagridview Based on ComboBox with SQL Server

Filling Data in the Datagridview Based on ComboBox with SQL Server in C#

In this tutorial, I’m going to show you how to fill the data in the Datagridview based on Combobox using C# and SQL Server. 

The process of this method is very simple, wherein you can easily retrieve the list of records that you have saved in the database and be loaded into the list control of a Combobox in the Datagriview.

These are the following steps:

note : For the database of this project just click here.

Step 1. Open Microsoft Visual Studio and create a new windows form application in C#. Then, drag a DataGridview on the form.

Step 2. Go to the solution explorer, click the “code view” to display the code editor.

Step 3. Declare and initialize all classes that are needed.

 //initializes new instance 
 SqlConnection con = new SqlConnection();
 SqlDataAdapter da = new SqlDataAdapter();
 SqlCommand cmd = new SqlCommand();
 DataTable dt = new DataTable();

Step 4. Create a method for filling data in a ComboBox.

private void LoadCombo()
 {
 //opening connection
 con.Open();
 try
 {
 //initialize a new instance of sqlcommand
 cmd = new SqlCommand();
 //set a connection used by this instance of sqlcommand
 cmd.Connection = con;
 //set the sql statement to execute at the data source
 cmd.CommandText = "SELECT * FROM tblsubject";
 //initialize a new instance of sqlDataAdapter
 da = new SqlDataAdapter();
 //set the sql statement or stored procedure to execute at the data source
 da.SelectCommand = cmd;
 //initialize a new instance of DataTable
 dt = new DataTable();
 //add or resfresh rows in the certain range in the datatable to match those in the data source.
 da.Fill(dt);

 //initialize the combox column
 DataGridViewComboBoxColumn cbo = new DataGridViewComboBoxColumn();
 //add data in the combobox
 foreach (DataRow r in dt.Rows)
 {
 //adding a list of records in the combobox
 cbo.Items.Add(r.Field<string>("SUBJCODE"));
 //name of combo box
 cbo.Name = "Subject";
 }
 //adding combobox in the datagridview 
 dataGridView1.Columns.Add(cbo);
 

 }
 catch (Exception ex)
 {
 //catching error 
 MessageBox.Show(ex.Message);
 }
 //release all resources used by the component
 da.Dispose();
 //closing connection
 con.Close();
 }

Step 5. Go back to the design view, double-click the form and do the following codes for setting up the connection between SQL Server 2005 Express Edition and C#.Net. Then, call the “LoadCombo” method that you have created.

//set a connection between SQL server and Visual C#
 con.ConnectionString = "Data Source=.\\SQLEXPRESS;Database=dbsubject;trusted_connection=true;";

 LoadCombo();

Output:

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