This tutorial will teach you how to Populate DataGridView based on Combobox selected using C#.net and Microsoft SqlServer. Import the Namespace using System.Data.SqlClient; Establish the database Connection SqlConnection con = new SqlConnection("server=.;database=ads;user id=sa;password=123;"); SqlCommand cmd; SqlDataAdapter dr; DataSet ds; ComboBox Selected Event if (comboBox1.SelectedItem.ToString() == "Students") { try { dataGridView1.Refresh(); con.Open(); DataTable dt = new DataTable(); dr = new SqlDataAdapter("select …