查詢語句
select issue.id,issue.area,issue.insert_uid,`user`.school_id,school.`name`,school.area as area1 from issue,user,school where issue.insert_uid=`user`.id and `user`.school_id=school.id
更新語句
UPDATE issue INNER JOIN user ON `issue`.insert_uid and `user`.id INNER JOIN
(SELECT issue.id as id,issue.insert_uid as uid,`user`.school_id as school_id,school.area as area1 from issue,user,school
where issue.insert_uid=`user`.id and `user`.school_id=school.id) AS T1
ON issue.insert_uid=T1.uid
SET issue.area=T1.area1