使用inner join实现多表连接查询

1.不是用inner join四表连接查询

declare @username nvarchar(100)
declare @userpwd nvarchar(100)
set @username='admin'
set @userpwd='password'
SELECT  * FROM aspnet_Membership aM, aspnet_Users aU,Users U,UserRoles UR where aM.UserId=aU.UserId and
aU.UserName=U.Username and U.UserID=UR.UserID
and U.Username=@username and aM.password=@userpwd and UR.roleid=0

2.使用inner join四表连接查询

declare @username nvarchar(100)
declare @userpwd nvarchar(100)
set @username='admin'
set @userpwd='password'
select  *  from  (((aspnet_Membership INNER JOIN aspnet_users ON aspnet_Membership.UserId = aspnet_users.UserId)
INNER JOIN Users ON aspnet_users.username=Users.username)INNER JOIN UserRoles ON Users.userid=UserRoles.userid)
where Users.Username=@username and aspnet_Membership.password=@userpwd and UserRoles.roleid=0