Mysql更新关联子查询报错

报错内容：sql  1093 - You can't specify target table 'u' for update in FROM clause

错误原因： if you're doing an UPDATE/INSERT/DELETE on a table, you can't reference that table in an inner query

解决方法： (you can however reference a field from that outer table...)

错误的sql语句

 update gg_platform_navtree u set u.pid = (select id from gg_platform_navtree s where s.pid = u.pid and s.isleaf = 0 ) where u.isleaf = 1;

通过解决方案转换后的sql语句

update gg_platform_navtree u set u.pid = (select id from (select * from gg_platform_navtree) s where s.pid = u.pid and s.isleaf = 0 ) where u.isleaf = 1;