sql server ， C# 多条语句事务处理，失败回滚

 1         public bool mysql()
 2         {
 3             conn.Open();
 4             SqlTransaction mytran = conn.BeginTransaction();//形如数据事务
 5             SqlCommand cmd;
 6             try
 7             {
 8                 string sql = "********";//sql语句1
 9                 cmd = new SqlCommand(sql, conn);
10                 cmd.Transaction = mytran;
11                 cmd.ExecuteNonQuery();
12 
13                 sql = "*****";//sql语句2
14                 cmd = new SqlCommand(sql, conn);
15                 cmd.Transaction = mytran;
16                 cmd.ExecuteNonQuery();
17 
18                 mytran.Commit();//提交数据库事务
19                 return true;
20             }
21             catch (Exception ex)
22             {
23                 mytran.Rollback();//回滚（出错的时候)
24                 return false;
25             }
26             finally
27             {
28                 conn.Close();
29             }
30         }