返回空行當沒有記錄sql server

Question

我有一個表tblAccount。我想從表格中得到前四排。如果沒有記錄，我想獲得4個空白行。

select * 
from tblAccount 

o/p 
---- 
AccountID AccountNo 
1   #101 
2   #102 
NULL  NULL 
NULL  NULL 

以上應該是結果，如果兩個記錄在那裏。

Answer 1

這應該工作。你可以用臨時表做同樣的事情，只需給它適當數量的字段和行。

with meganull(a,b) as (
    select CAST(null as int), 
      CAST(null as varchar(max)) 
    union all 
    select * 
    from meganull 
) 
select top 4 * 
from (
    select * 
    from tblAccount 
    union all 
    select * 
    from meganull) as sq 

Answer 2

SQLFiddle demo

select TOP 4 AccountID,AccountNo 
from 
(
select 0 as srt,AccountID,AccountNo from tblAccount 
union all 
select 1 as srt,NULL as AccountID, NULL as AccountNo 
union all 
select 2 as srt,NULL as AccountID, NULL as AccountNo 
union all 
select 3 as srt,NULL as AccountID, NULL as AccountNo 
union all 
select 4 as srt,NULL as AccountID, NULL as AccountNo 
) as t 
order by srt,AccountID 

Answer 3

試試這個...

Select * FROM (VALUES (1),(2),(3),(4)) AS value(tmpID) left join 
(
select Row_Number() over (order by AccountID) as RowCtr, * 
from tblAccount 
) accountTable on tmpID = accountTable.RowCtr 

我使用了類似的技術時，我就想辦法強制一定的行數在SSRS報告中顯示，其中空白行表示物理機架中的空點。