2个表查询加where User.GroupID=3查的怎么还是所有的数据

Question

select User.UserID,User.UserName,User.UserFace,Contacter.TrueName,Contacter.Address,Contacter.Sex,Contacter.Company,Contacter.Department,Contacter.OfficePhone,User.GroupID from User,Contacter where User.GroupID=3

Answer 1

from User,Contacter 
where User.GroupID=3
User,Contacter 沒有條件關聯~~

Answer 2

select User.UserID,User.UserName,User.UserFace,Contacter.TrueName,Contacter.Address,Contacter.Sex,Contacter.Company,Contacter.Department,Contacter.OfficePhone,User.GroupID from User,Contacter where User.GroupID=3 and User.字段=Contacter.字段

Answer 3

select User.UserID,User.UserName,User.UserFace,Contacter.TrueName,Contacter.Address,Contacter.Sex,Contacter.Company,Contacter.Department,Contacter.OfficePhone,User.GroupID from
 User,Contacter where User.GroupID=3

Answer 4

select User.UserID,User.UserName,User.UserFace,Contacter.TrueName,Contacter.Address,Contacter.Sex,Contacter.Company,Contacter.Department,Contacter.OfficePhone,User.GroupID from User,Contacter where 这里还少了条件User.GroupID=3

Answer 5

select 
User.UserID,
User.UserName,
User.UserFace,
Contacter.TrueName,
Contacter.Address,
Contacter.Sex,
Contacter.Company,
Contacter.Department,
Contacter.OfficePhone,
User.GroupID 
from 
User,Contacter 
where 
User.GroupID=3
and
两条的连接条件

Answer 6

select User.UserID,User.UserName,User.UserFace,Contacter.TrueName,Contacter.Address,Contacte
r.Sex,Contacter.Company,Contacter.Department,Contacter.OfficePhone,User.GroupID from User,Contacter where User.GroupID=3 and User.字段=Contacter.字段

Answer 7

你的这条语句会出现Contacter表里的所有数据，但User表里只出现GroupID＝3的数据。