SQL语句关于树查询

 1 .菜单树查询
SELECT
 2     A.*
 3 FROM
 4     MENU A
 5 WHERE
 6     A.ID IN (31, 51)
 7 UNION
 8     SELECT
 9         C.*
10     FROM
11         MENU C
12     WHERE
13         C.ID IN (
14             SELECT
15                 B.PARENTID
16             FROM
17                 MENU B
18             WHERE
19                 B.ID IN (31, 51) and B.PARENTID!=0
20         )

 1 SELECT
 2 U.UUID,
 3 U.USERACCOUNT,
 4 U. PASSWORD,
 5 U.IDENTITY,
 6 U.AREA,
 7 U.ROLE_UUID ROLEUUID,
 8 U.CREATETIME,
 9 R.ROLENAME
10 FROM
11 USERS U
12 LEFT JOIN ROLE R ON U.ROLE_UUID=R.UUID
13 WHERE
14 1 = 1
15 LIMIT ?, ?