MySQL的異常處理分析如下:
標准格式
DECLARE handler_type HANDLER FOR condition_value[,...] statement handler_type: CONTINUE | EXIT | UNDO --這個暫時不支持 condition_value: SQLSTATE [VALUE] sqlstate_value | condition_name | SQLWARNING | NOT FOUND | SQLEXCEPTION | mysql_error_code condition_value細節
1、常用MYSQL ERROR CODE 列表
http://dev.mysql.com/doc/refman/5.0/en/error-messages-server.html
更多錯誤列表見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以及其他的標准.
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開頭的錯誤代碼
NOT FOUND 代表所有以02開頭的錯誤代碼,當然也可以代表一個游標到達數據集的末尾。
SQLEXCEPTION 代表除了SQLWARNING和NOT FOUND 的所有錯誤代碼
3、我們現在就用手冊上的例子
CREATE TABLE t (s1 int,primary key (s1)); mysql> use t_girl Database changed mysql> 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; -- 遇到重復鍵值就退出 -> 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$$ Query OK, 0 rows affected (0.01 sec) mysql> DELIMITER ; mysql> call handlerdemo(); Query OK, 0 rows affected (0.00 sec) mysql> select @x; +------+ | @x | +------+ | 3 | +------+ 1 row in set (0.00 sec) mysql> call handlerdemo(); Query OK, 0 rows affected (0.00 sec) mysql> select @x; +------+ | @x | +------+ | 3 | +------+ 1 row in set (0.00 sec) mysql>
可以看到,始終執行到最後。
當然,上面的SQLSTATE '23000'可以替換為1062
我們來看一下警告。
mysql> alter table t add s2 int not null; Query OK, 0 rows affected (0.01 sec) Records: 0 Duplicates: 0 Warnings: 0
此列沒有默認值,插入的時候會出現警告或者1364錯誤提示。
mysql> DELIMITER $$ 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)