private void Form1_Load(object sender, EventArgs e)        {            string strCon = "Server=localhost;User Id=sa;Pwd=;DataBase=my";//定义数据库连接字符串            SqlConnection sqlcon = new SqlConnection(strCon);//实例化数据库连接对象            SqlDataAdapter sqlda_1 = new SqlDataAdapter("select * from S",sqlcon);//实例化数据库桥接器对象            SqlDataAdapter sqlda_2 = new SqlDataAdapter("select * from Y",sqlcon);//实例化数据库桥接器对象            DataSet myds = new DataSet();//实例化数据集对象            sqlda_1.Fill(myds,"table_name_1");//填充数据集中的指定表            sqlda_2.Fill(myds, "table_name_2");//填充数据集中的指定表            //dataGridView1.DataSource = myds.Tables["table_name_1"];//为dataGridView1指定数据源            //dataGridView1.DataSource = myds.Tables[0];//为dataGridView1指定数据源table_name_1<=>0            //dataGridView1.DataSource = myds.Tables["table_name_2"];table_name_2<=>1            dataGridView1.DataSource = myds.Tables[1];        }