;with cte as
(
  select 1 as row
  union 
  select 2
  union 
  select 3
  union
  select 4
  union
  select 5
)

select a.row,isnull(b.score,0) score
from cte a left join tb b on a.row = b.id

------解决方案--------------------
select b.id,isnull(a.score,0) as score
from
(select 1 as id union select 2 union select 3 union select 4 union select 5) b
left join a on a.id=b.id

------解决方案--------------------
SQL code
create table tb(id int,score int)
insert into tb select 1,80
insert into tb select 2,90
insert into tb select 3,100
go
select a.number,isnull(b.score ,0)score
from master..spt_values a left join tb b on a.number=b.id
where type='p' and a.number in(1,2,3,4,5)
/*
number      score
----------- -----------
1           80
2           90
3           100
4           0
5           0

(5 行受影响)

*/
go
drop table tb

------解决方案--------------------
SQL code
IF NOT OBJECT_ID('tb') IS NULL 
    DROP TABLE tb
Go
CREATE TABLE tb ( [id] INT, [score] INT )
INSERT  tb
        SELECT  1 ,
                80
        UNION ALL
        SELECT  2 ,
                90
        UNION ALL
        SELECT  3 ,
                100
Go
SELECT  a.number ,
        ISNULL(b.[score], 0) [score]
FROM    master.dbo.spt_values a
        LEFT JOIN dbo.TB b ON a.number = b.ID
WHERE   type = 'P'
        AND number IN ( 1, 2, 3, 4, 5 )
        /*
        number      score
----------- -----------
1           80
2           90
3           100
4           0
5           0

        */

------解决方案--------------------
SQL code
select * from a right join (select 1 as id union select 2 
                            union select 3 union select 4 union select 5) b
on a.id =b.id

------解决方案--------------------
探讨

select b.id,isnull(a.score,0) as score
from
(select 1 as id union select 2 union select 3 union select 4 union select 5) b
left join a on a.id=b.id


------解决方案--------------------
SQL code

if object_id('tb','U') is not null
   drop table tb
go
create table tb
(
 id int,
 score int
)
go
insert into tb
select 1,80 union all
select 2,90 union all
select 3,100
go
select number,isnull(score,0) from master..spt_values a left join tb b on a.number=b.id where type='p' and number between 1 and 5
go
/*
number      
----------- -----------
1           80
2           90
3           100
4           0
5           0

(5 行受影响)
*/