SQL学习

        --这个没问题
declare @UID int
set @UID=3
select * from T_Role_Module where RoleID 
in (select RoleID from T_User_Role where UserID=@UID)

        --这个有错，求教育
declare @RIDs table(RoleID int),@UID int
set @UID=3

insert into @RIDs
select RoleID from T_User_Role where UserID=@UID

select * from T_Role_Module where RoleID 
in @RIDs

[最优解释]

declare @RIDs table(RoleID int),@UID int    set @UID=3     insert into @RIDs    select RoleID from T_User_Role where UserID=@UID     select * from T_Role_Module where RoleID     in （select * from @RIDs)

[其他解释]

 
DECLARE @RIDs TABLE ( RoleID INT )
DECLARE @UID INT    
SET @UID = 3       
INSERT  INTO @RIDs
        SELECT  RoleID
        FROM    T_User_Role
        WHERE   UserID = @UID       
SELECT  A.*
FROM    T_Role_Module a
        INNER JOIN @RIDs b ON A.roleid = b.roleid

[其他解释]

declare @RIDs table(RoleID int)
declare @UID int
    set @UID=3
 
insert into @RIDs
select RoleID from T_User_Role where UserID=@UID
 
select * from T_Role_Module where RoleID  in (select RoleID from @RIDs)

[其他解释]
declare @RIDs table(RoleID int),@UID int
set @UID=3
insert into @RIDs
select RoleID from T_User_Role where UserID=@UID
select * from T_Role_Module where RoleID in (select roleid from @RIDs)