请问.效率问题
igelf 2008-09-26 01:29:47 Select [user].id,profile.name
from [user] left join profile on [user].id=profile.userid
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Select [user].id,(select name from profile where userid=[user].id)as name
from [user]
上面两种哪个效率会高点.
还有如果多个哪个效率高.
Select
[user].id,
profile.name,
profile.name2
from [user] left join profile on [user].id=profile.userid
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Select
[user].id,
(select name from profile where userid=[user].id)as name ,
(select name2 from profile where userid=[user].id)as name2
from [user]