Return value if Row(Record) does not Exist in SQL SERVER

Question

I have a table named as 'Banners' with following data and structure:

ID  Name   Enabled SectionID Slot

112 kabob     1      231      6 
198 Omega-5   1      231      1 
165 eeee      1      231      3 
171 iiii      1      231      3 
172 jjjj      1      231      3
113 cooked    1      231      4
114 coconut   1      231      5 

Note : There can be in all 6 slots (1 to 6) in Slot column, but i have not added a record for slot 2. ie row does not exist for slot 2.

Query :

SELECT DISTINCT Slot AS '231' FROM Mercola_Banners WHERE      
 SectionID = 231 and ENABLED = 1    
 GROUP BY slot  
 HAVING COUNT(1) <=15

Result i get:

  231 
1  1
2  3
3  4
4  5
5  6

As, i have not added any record for slot 2 it does not show in result. but i want that slot in my result. As it does not have any record for slot 2. OR Count <15. As shown below.

Expected Result :

  231 
1  1
2  2
3  3
4  4
5  5
6  6

Answer 1

This is too long for a comment.

Why are you bothering with such a complicated query? Why not just do:

select n as [231]
from (select 1 as n union all select 2 union all select 3 union all select 4 union all
      select 5 union all select 6
     ) n

I don't see what the results you want really have to do with the data in the tables.

EDIT:

If I understand correctly, you still do want to apply the other criteria. You are saying that 2 meets the criteria because there are fewer than 15 rows. But it doesn't make it into the output because there are no rows. Here is one solution to this problem:

SELECT n.n AS [231]
FROM (select 1 as n union all select 2 union all select 3 union all select 4 union all
      select 5 union all select 6
     ) n LEFT JOIN
     Mercola_Banners mb
     ON n.n = mb.slot and mb.SectionID = 231 and mb.ENABLED = 1    
GROUP BY n.n  
HAVING COUNT(mb.slot) <= 15

Answer 2

The clean way is to have a table, for example called slots Then you can do the following query:

select slotid, (select count(*) from banners b where b.slot = slotid) as count 
from slots.

This way if you add more slots in the future, you only need to add them to that table.