MySql 遞歸查詢

一、遞歸語句

-- 向下遞歸函數
SELECT GROUP_CONCAT('''', pk_dept , '''')  FROM rz.dept WHERE FIND_IN_SET(fr_pk_dept,'1070')>0;

結果：

設置某個部門下的所有子部門為無效：

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

二、自定義遞歸函數

利用find_in_set()函數和group_concat()函數實現遞歸查詢：

1，向下遞歸：

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;

調用方式：

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

2，向上遞歸：

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;

調用方式：

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