DECLARE CONTINUE HANDLER FOR NOT FOUND 解释
在mysql的存储过程中经常会看到这句话:DECLARE CONTINUE HANDLER FOR NOT FOUND。 它的含义是:若没有数据返回,程序继续,并将变量IS_FOUND设为0 ,这种情况是出现在select XX into XXX from tablename的时候发生的。
2.示例:
/*建立存储过*/ CREATE PROCEDURE useCursor() BEGIN /*局部变量的定义*/ declare tmpName varchar(20) default ; declare allName varchar(255) default ; declare cur1 CURSOR FOR SELECT name FROM test.level ; declare CONTINUE HANDLER FOR SQLSTATE 02000 SET tmpname = null; #也可以这么写 #DECLARE CONTINUE HANDLER FOR NOT FOUND SET tmpname = null; OPEN cur1; FETCH cur1 INTO tmpName; WHILE ( tmpname is not null) DO set tmpName = CONCAT(tmpName ,";") ; set allName = CONCAT(allName ,tmpName) ; FETCH cur1 INTO tmpName; END WHILE; CLOSE cur1; select allName ; END; call useCursor()
