//连接语句
public readonly string sqlconn = ConfigurationManager.ConnectionStrings["Transaction_9_30ConnectionString"].ConnectionString; //ExecuteQuery LinqToSqlDataContext LinqToSql = new LinqToSqlDataContext(sqlconn);
//var result = from query in LinqToSql.Class select query;
List<Class> result = LinqToSql.ExecuteQuery<Class>("select * from Class").ToList();
dataGridView1.DataSource = result; //ExecuteCommand string StringText = textBox1.Text;
linq.ExecuteCommand("update Class set ClassName={0} where ClassID='5'", StringText);
IEnumerable<Class> sell = linq.ExecuteQuery<Class>("select * from Class").ToList();
dataGridView2.DataSource = sell;