string sql = "USE Car_"+dateTimePicker1.Value.Year+"\r\nSELECT guid,A,B,C FROM System";
var ds = SqlHelper.ExecuteDataset(Connstr, CommandType.Text, sql);
dataGridView1.DataSource = ds.Tables[0].DefaultView;
想将A列中的值读取出来,进行运行后再显示到dataGridView1中,怎样实现呢?