A solution to the problem that MySQL cannot update the query result set

1、update The table and... Of the subquery contained in the update When the table of is the same table , Report errors

--  Wrong cases 
UPDATE tab_user 
SET sex = ' Woman ' 
WHERE
	uid IN (
	SELECT
		uid 
	FROM
		tab_user 
WHERE
	STATUS = 'N')
--  Report errors ：You can't specify target table 'tab_user' for update in FROM clause

--  terms of settlement 
--  Nest the subquery result set one level select And take an alias to solve 
UPDATE tab_user 
SET sex = ' Woman ' 
WHERE
	uid IN (
	SELECT
		uid 
FROM
	( SELECT uid FROM tab_user WHERE `status` = 'N' ) AS temp)

2. When you need to modify the result set of a linked table query, you will be prompted that you cannot update Result set

--  Solution 
--  Modify table join query table , direct update Modify the table 
UPDATE A surface  AS i
RIGHT JOIN (
	SELECT
		b.* 
	FROM
		A surface  a
		INNER JOIN B surface  b ON a.studentcode = b.CODE 
	WHERE
		a.schoolitemcode != b.schoolitemcode 
	) AS s ON i.studentcode = s.CODE 
	SET i.schoolitemcode = s.schoolitemcode