Question

sql语句多表联查问题

一共有4个表:news_info,news_class,city_info,user_info

news_info 字段：id,news_tit，news_content，addDate，tj，city_id

news_class 字段：id,news_class，news_class_fid，news_class_px，user_id

city_info 字段：id,city，fid

user_info 字段：id,username,userEmail

先添加 news_info表 8条新闻数据，user_info表3条用户数据， city_info表 5个城市

news_class 表4条数据

后查询 news_info 里的news_tit,news_content ,
news_class里的news_class
city_info 里的city
user_info 里的username,useremail
多谢了！

Answer 1

select a.news_tit,a.news_content ,b.news_class,c.city,
d.username,d.useremail
from news_info a,news_class b,city_info c,user_info d
where a.city_id=c.id and b.user_id=d.id and a.id=b.news_class_fid
你看一下这样可不可以

Answer 2

SELECT AA.NEWS_TIT,AA.NEWS_CONTENT,BB.NEWS_CLASS,CC.CITY,DD.USERNAME,
DD.USEREMAIL
FROM NEWS_INFO AA,NEWS_CLASS BB,CITY_INFO CC,USER_INFO DD