【MySQL】MySQL創建函數（FUNCTION）

代碼示例

DROP FUNCTION IF EXISTS `getChildID`;
DELIMITER ;;
CREATE DEFINER=`seul`@`%` FUNCTION `getChildID`(areaId varchar(20)) RETURNS varchar(4000) CHARSET utf8
BEGIN
            DECLARE sTemp VARCHAR(4000);
            DECLARE sTempChd VARCHAR(4000);
            SET sTemp='';
            SET sTempChd = CAST(areaId AS CHAR);
            WHILE sTempChd IS NOT NULL DO
						IF sTemp!='' THEN
            SET sTemp= CONCAT(sTemp,',',sTempChd);
						ELSE
					  SET sTemp=sTempChd;
						END IF;
            SELECT GROUP_CONCAT(id) INTO sTempChd FROM z_area WHERE FIND_IN_SET(CAST(parent_id AS SIGNED),sTempChd)>0;
            END WHILE;
            RETURN sTemp;
            END
;;
DELIMITER ;

-- ----------------------------
-- Function structure for getParentID
-- ----------------------------
DROP FUNCTION IF EXISTS `getParentID`;
DELIMITER ;;
CREATE DEFINER=`seul`@`%` FUNCTION `getParentID`(areaId varchar(20)) RETURNS varchar(4000) CHARSET utf8
BEGIN
            DECLARE sTemp VARCHAR(4000);
            DECLARE sTempChd VARCHAR(4000);
            SET sTemp='';
 
						SELECT group_concat(T2.id) INTO sTemp
            FROM (
                  SELECT
                    @r AS _id,
                    (SELECT @r := parent_id FROM z_area WHERE id = _id) AS parent_id,
                    @l := @l + 1 AS lvl FROM (SELECT @r := areaId, @l := 0) vars,
                    z_area h WHERE @r <> 0 AND parent_id > 0
                 ) T1 JOIN z_area T2 ON T1._id = T2.id ORDER BY T1.lvl DESC;
						
            RETURN sTemp;
            END
;;
DELIMITER ;