有谁可以帮我把这条sql语句改改?

[宰恩灬威廉姆斯]

有谁可以帮我把这条sql语句改改?
select * from table1 where id in(select fid form table2 where id in(select info_id from table3 )) and id in(select * from table4)
其中用了4个in,效率比较低,table2是放id,fid的字段.其实前面一半可以写成select * from table1,table2,table3 where table1.id=table2.id and table2.fid=table3.id不过怎么接上后面的and id in(select * from table4)
?

[ronanlin]

不知可不可以用inner join

[panyee]

and table1.id in (select * from table4)

[kysyuan]

select a.*,b.fid,c.info_id,d.id
from table1 a inner join table2 b on a.id=b.fid
inner join table3 on b.fid=c.info_id
inner join table4 d on a.id=d.id

[basil]

你的第一个sql语句可能有错误，如果没有错的话，table4里应该只有一个字段。
第二句应写成select * from table1,table2,table3,table4 where table1.id=table2.fid and table2.id=table3.info_id and table1.id=table4.id,但这和第一句并不完全等价，第二句中完全相等的值也会列出来，可以考虑用inner join.

[大健]

SELECT table1.*
FROM table1,table2,table3,table4
WHERE table1.[id] = table2.fid AND
table2.[id] = table3.info_id AND
table1.[id] = table4.[id]

[大健]

SELECT table1.*
FROM table1,table2,table3,table4
WHERE table1.[id] = table2.fid AND
table2.fid = table3.info_id AND
table1.[id] IN (select * from table4)

[basil]

select * from table1 a inner join table2 b on a.id=b.fid
inner join table3 c on b.id=c.info_id
inner join table4 d on a.id=d.id