Sql-事务

private void Form1_Load(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(@"SERVER=localhost;UID=sa;DATABASE=GG;MultipleActiveResultSets =true;PWD=123456");
con.Open();
////创建事务并赋值
SqlTransaction tran= con.BeginTransaction();
//创建SqlCommand实例
SqlCommand _delete=con.CreateCommand();
SqlCommand _insert = con.CreateCommand();
SqlCommand _select = con.CreateCommand();
SqlCommand _update = con.CreateCommand();
//通过同一个SqlConnection创建的SqlCommand，每一个都需要事务，否则报错
_delete.Transaction = tran;
_insert.Transaction = tran;
_select.Transaction = tran;
_update.Transaction = tran;

try
{
_delete.CommandText = "delete from t_user where no=11 or no=12";
_delete.ExecuteNonQuery();
_insert.CommandText = "insert t_user (no,age,name) values(11,111,1111)";
_insert.ExecuteNonQuery();
////在SQL语句未执行完提交，后面的语句报错不会回滚
////tran.Commit();
_update.CommandText = "update t_user set name=12,no=12,age=12 wh2ere no=11";
_update.ExecuteNonQuery();
_select.CommandText = "select * from t_user";
SqlDataAdapter adt = new SqlDataAdapter(_select);
DataTable dt = new DataTable();
adt.Fill(dt);
dataGridView1.DataSource = dt;
//提交事务（在与本事务相关sql语句执行完之后提交）
tran.Commit();
}
catch (Exception ex)
{
//从挂起状态回滚事务，不需要写tran.Rollback();，报错会自动运行
//tran.Rollback();
MessageBox.Show(ex.Message.ToString(), this.Text, MessageBoxButtons.OK, MessageBoxIcon.Question);
}
finally
{
con.Close();
}
}