try this,
try
{
using (SqlConnection con = new SqlConnection(YOUR CONNECTION STRING))
{
con.Open();
using (SqlDataAdapter adapt = new SqlDataAdapter("select * from client", con))
{
DataTable ds = new DataTable();
adapt.Fill(ds);
dataGridView1.DataSource = ds;
}
}
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}