MySQL的異常處理分析如下:
標準格式
DECLARE handler_type HANDLER FOR condition_value[,...] statementhandler_type: CONTINUE | EXIT | UNDO --這個暫時不支援condition_value: SQLSTATE [VALUE] sqlstate_value | condition_name | SQLWARNING | NOT FOUND | SQLEXCEPTION | mysql_error_codecondition_value細節
1、常用MYSQL ERROR CODE 列表
http://dev.mysql.com/doc/refman/5.0/en/error-messages-server.html
更多錯誤清單見MySQL安裝路徑下
比如我的/usr/local/mysql/share/mysql/errmsg.txt
說明一下:SQLSTATE [VALUE] sqlstate_value這種格式是專門為ANSI SQL 和 ODBC以及其他的標準.
並不是所有的MySQL ERROR CODE 都映射到SQLSTATE。
2、如果你不想插ERROR CODE的話,就用速記條件來代替
SQLWARNING 代表所有以01開頭的錯誤碼
NOT FOUND 代表所有以02開頭的錯誤碼,當然也可以代表一個遊標到達資料集的末尾。
SQLEXCEPTION 代表除了SQLWARNING和NOT FOUND 的所有錯誤碼
3、我們現在就用手冊上的例子
CREATE TABLE t (s1 int,primary key (s1));mysql> use t_girlDatabase changedmysql> CREATE TABLE t (s1 int,primary key (s1));Query OK, 0 rows affected (0.00 sec)mysql> mysql> mysql> DELIMITER ||mysql> CREATE PROCEDURE handlerdemo () -> BEGIN -> DECLARE EXIT HANDLER FOR SQLSTATE '23000' BEGIN END; -- 遇到重複索引值就退出 -> SET @x = 1; -> INSERT INTO t VALUES (1); -> SET @x = 2; -> INSERT INTO t VALUES (1); -> SET @x = 3; -> END||Query OK, 0 rows affected (0.00 sec)mysql> DELIMITER ;mysql> call handlerdemo();Query OK, 0 rows affected (0.00 sec)mysql> select @x;+------+| @x |+------+| 2 | +------+1 row in set (0.00 sec)mysql> call handlerdemo();Query OK, 0 rows affected (0.00 sec)mysql> select @x;+------+| @x |+------+| 1 | +------+1 row in set (0.00 sec)mysql>
現在來看一下遇到錯誤繼續的情況
mysql> truncate table t;Query OK, 0 rows affected (0.01 sec)mysql> DELIMITER $$mysql> DROP PROCEDURE IF EXISTS `t_girl`.`handlerdemo`$$Query OK, 0 rows affected (0.00 sec)mysql> CREATE DEFINER=`root`@`localhost` PROCEDURE `handlerdemo`() -> BEGIN -> DECLARE CONTINUE HANDLER FOR SQLSTATE '23000' BEGIN END; -> SET @x = 1; -> INSERT INTO t VALUES (1); -> SET @x = 2; -> INSERT INTO t VALUES (1); -> SET @x = 3; -> END$$Query OK, 0 rows affected (0.01 sec)mysql> DELIMITER ;mysql> call handlerdemo();Query OK, 0 rows affected (0.00 sec)mysql> select @x;+------+| @x |+------+| 3 | +------+1 row in set (0.00 sec)mysql> call handlerdemo();Query OK, 0 rows affected (0.00 sec)mysql> select @x;+------+| @x |+------+| 3 | +------+1 row in set (0.00 sec)mysql>
可以看到,始終執行到最後。
當然,上面的SQLSTATE '23000'可以替換為1062
我們來看一下警告。
mysql> alter table t add s2 int not null;Query OK, 0 rows affected (0.01 sec)Records: 0 Duplicates: 0 Warnings: 0
此列沒有預設值,插入的時候會出現警告或者1364錯誤提示。
mysql> DELIMITER $$mysql> DROP PROCEDURE IF EXISTS `t_girl`.`handlerdemo`$$Query OK, 0 rows affected, 1 warning (0.00 sec)mysql> CREATE DEFINER=`root`@`localhost` PROCEDURE `handlerdemo`() -> BEGIN -> DECLARE CONTINUE HANDLER FOR 1062 BEGIN END; -> DECLARE CONTINUE HANDLER FOR SQLWARNING -> BEGIN -> update t set s2 = 2; -> END; -> DECLARE CONTINUE HANDLER FOR 1364 -> BEGIN -> INSERT INTO t(s1,s2) VALUES (1,3); -> END; -> SET @x = 1; -> INSERT INTO t(s1) VALUES (1); -> SET @x = 2; -> INSERT INTO t(s1) VALUES (1); -> SET @x = 3; -> END$$Query OK, 0 rows affected (0.00 sec)mysql> DELIMITER ;mysql> call handlerdemo();Query OK, 0 rows affected (0.00 sec)mysql> select * from t;+----+----+| s1 | s2 |+----+----+| 1 | 3 | +----+----+1 row in set (0.00 sec)
遇到錯誤的時候插入的新記錄。
mysql> select @x;+------+| @x |+------+| 3 | +------+1 row in set (0.00 sec)