select id from fanwe_city where pid=(SELECT cityid FROM fanwe_article where id=5) or id=(SELECT cityid FROM fanwe_article where id=5) order by id desc limit 0,50这里出现了2次:SELECT cityid FROM fanwe_article where id=5怎么写这个sql可以简化为1个呢
调试欢乐多
from fanwe_city A,fanwe_article B
where B.id=5 and (A.pid=B.cityid or id=B.cityid)
order by A.id desc
limit 0,50;
from fanwe_city A,fanwe_article B
where B.id=5 and (A.pid=B.cityid or id=B.cityid)
order by A.id desc
limit 0,50;