MySQL 错误处理例子

from http://www.devshed.com/c/a/MySQL/Error-Handling-Examples/

 

Error Handler Examples

Here are some examples of handler declarations:

• If any error condition arises (other than a NOT FOUND ), continue execution after setting l_error=1 :
  
    DECLARE CONTINUE HANDLER FOR SQLEXCEPTION
    SET l_error=1; 
• If any error condition arises (other than a NOT FOUND ), exit the current block or stored program after issuing a ROLLBACK statement and issuing an error message: 
  
    DECLARE EXIT HANDLER FOR SQLEXCEPTION
    BEGIN
        ROLLBACK;
        SELECT 'Error occurred – terminating';
    END;  
• If MySQL error 1062 (duplicate key value) is encountered, continue execution after executing the SELECT statement (which generates a message for the calling program):
  
    DECLARE CONTINUE HANDER FOR 106 2 
        SELECT 'Duplicate key in index';
• If SQLSTATE 23000 (duplicate key value) is encountered, continue execution after executing the SELECT statement (which generates a message for the calling program):
  
    DECLARE CONTINUE HANDER FOR SQLSTATE '23000'
        SELECT 'Duplicate key in index';  
• When a cursor fetch or SQL retrieves no values, continue execution after setting l_done=1 :
  
    DECLARE CONTINUE HANDLER FOR NOT
  FOUND
        SET l_done=1; 
• Same as the previous example, except specified using a SQLSTATE variable rather than a named condition:
  
    DECLARE CONTINUE HANDLER FOR SQLSTATE '02000 '
        SET l_done=1; 
• Same as the previous two examples, except specified using a MySQL error code variable rather than a named condition or SQLSTATE variable:
  
    DECLARE CONTINUE HANDLER FOR 1329
        SET l_done=1;

错误处理例子

有几种错误处理的声明形式：

§         如果任何错误（不是 NOT FOUND ） , 设置 l_error 为 1 后继续执行：

  DECLARE CONTINUE HANDLER FOR SQLEXCEPTION
  SET l_error=1;

§         如果发生任何错误（不是 NOT FOUND）， 执行 ROLLBACK和产生一条错误消息后退出当前块或存储过程。

DECLARE EXIT HANDLER FOR SQLEXCEPTION
  BEGIN
      ROLLBACK;
      SELECT 'Error occurred – terminating';
  END;  

§         如果 MySQL 1062错误 (重复的健值 )发生，执行 SELECT语句（向调用程序发一条消息）后继续执行

DECLARE CONTINUE HANDER FOR 106 2 
      SELECT 'Duplicate key in index';

§         如果 SQLSTATE 2300错误 (重复的健值 )发生，执行 SELECT语句（向调用程序发一条消息）后继续执行

DECLARE CONTINUE HANDER FOR SQLSTATE '23000'
      SELECT 'Duplicate key in index';  

§         当游标或者 SQL 选择语句没有返回值时，设置 l_done=1 后继续执行

DECLARE CONTINUE HANDLER FOR NOT
FOUND
      SET l_done=1; 

§         此例除了用 SQLSTATE 变量而不是命名条件以外，跟前一个例子一样

  DECLARE CONTINUE HANDLER FOR SQLSTATE '02000 '
      SET l_done=1; 

§         此例除了用 MySQL 的错误码变量而不是命名条件或者 SQLSTATE 变量以外，跟前两个例子一样

DECLARE CONTINUE HANDLER FOR 1329
      SET l_done=1;