You can use below code :
string myConnection = conn.ConnectionString.ToString();
SqlDataAdapter sqlcom0 = new SqlDataAdapter("SELECT Id,Name,Pos,Loc FROM Employee", myConnection);
DataSet ds0 = new DataSet();
sqlcom0.Fill(ds0);
dataGridView1.DataSource = ds0.Tables[0].DefaultView;
dataGridView1.Columns[0].HeaderText = "A";
dataGridView1.Columns[1].HeaderText = "A1";
dataGridView1.Columns[2].HeaderText = "A2";
dataGridView1.Columns[3].HeaderText = "A3";
dataGridView1.Refresh();
Hope this helps if yes then accept and vote the answer otherwise revert back with your queries
--Rahul D.