MySql 递归查询

一、递归语句

-- 向下递归函数
SELECT GROUP_CONCAT('''', pk_dept , '''')  FROM rz.dept WHERE FIND_IN_SET(fr_pk_dept,'1070')>0;

结果：

设置某个部门下的所有子部门为无效：

update rz.dept set zt ='0' WHERE FIND_IN_SET(fr_pk_dept,'部门ID')>0;

二、自定义递归函数

利用find_in_set()函数和group_concat()函数实现递归查询：

1，向下递归：

DROP FUNCTION IF EXISTS queryChildrenAreaInfo;
CREATE FUNCTION queryChildrenAreaInfo(areaId INT) -- 或者 areaId char
RETURNS VARCHAR(4000)
BEGIN
DECLARE sTemp VARCHAR(4000);
DECLARE sTempChd VARCHAR(4000);

SET sTemp='$';
SET sTempChd = CAST(areaId AS CHAR);

WHILE sTempChd IS NOT NULL DO
SET sTemp= CONCAT(sTemp,',',sTempChd);
SELECT GROUP_CONCAT(id) INTO sTempChd FROM t_areainfo WHERE FIND_IN_SET(parentId,sTempChd)>0;
END WHILE;
RETURN sTemp;
END;

调用方式：

SELECT * FROM t_areainfo WHERE FIND_IN_SET(id,queryChildrenAreaInfo(4));

2，向上递归：

DROP FUNCTION IF EXISTS queryChildrenAreaInfo1;
CREATE FUNCTION queryChildrenAreaInfo1(areaId INT)
RETURNS VARCHAR(4000)
BEGIN
DECLARE sTemp VARCHAR(4000);
DECLARE sTempChd VARCHAR(4000);

SET sTemp='$';
SET sTempChd = CAST(areaId AS CHAR);
SET sTemp = CONCAT(sTemp,',',sTempChd);

SELECT parentId INTO sTempChd FROM t_areainfo WHERE id = sTempChd;
WHILE sTempChd <> 0 DO
SET sTemp = CONCAT(sTemp,',',sTempChd);
SELECT parentId INTO sTempChd FROM t_areainfo WHERE id = sTempChd;
END WHILE;
RETURN sTemp;
END;

调用方式：

SELECT * from t_areainfo where FIND_IN_SET(id,queryChildrenAreaInfo1(7));