SQL using count in case statement - sql

Question

I'm trying to group all activity where the count is less than 5 (for data sharing reasons).
The ID Code and ID Name give me high level numbers, but as soon as I include "shop code" I get some low level numbers for customers that go to odd shops once or twice.
Select Count(*) [Activity],
T.[ID Code],
T.[ID Name],
Case when Count(*) < 6 then 'Other Shop' Else T.Shop End [Shop Code]
From MyTable T
Group By T.[ID Code],
T.[ID Name],
Case when Count(*) < 6 then 'Other Shop' Else T.Shop End
But obviously I can't use a count in a case statement. I've tried some of the solutions to similar questions but none of them work!
Thanks

Answer 1

The problem is the GROUP BY:
Select Count(*) as [Activity],
T.[ID Code],
T.[ID Name],
(Case when Count(*) < 6 then 'Other Shop' Else T.Shop
End) as [Shop Code]
From MyTable T
Group By T.[ID Code],
T.[ID Name];
Aggregate functions (or expressions with aggregates) don't belong in the GROUP BY. These are calculated in the SELECT, not used to define groups.

Answer 2

You can use the HAVING and UNION ALL statement, like this:
Select Count(*) as [Activity],
T.[ID Code],
T.[ID Name],
'Other Shop' [Shop Code]
From MyTable T
Group By T.[ID Code],
T.[ID Name]
having Count(*) < 6
union all
Select Count(*) as [Activity],
T.[ID Code],
T.[ID Name],
T.Shop [Shop Code]
From MyTable T
Group By T.[ID Code],
T.[ID Name]
having Count(*) >= 6

Answer 3

select
count(*) as activity,
code,
name,
Case when Count(*) < 6 then 'Other Shop' Else shopcode End as shopcode
from mytable group by code, name ,shopcode

Answer 4

The example below is a test in SQL Server.
It uses a window function for count, to change the Shop code.
And then groups it all, including that modified shopcode.
declare #ShopTable table ([ID Code] varchar(30), [ID Name] varchar(30), Shop varchar(30));
insert into #ShopTable ([ID Code], [ID Name], Shop) values
('S1','Shop 1','AA'),
('S1','Shop 1','BB'),
('S1','Shop 1','BB'),
('S1','Shop 1','CC'),
('S1','Shop 1','CC'),
('S1','Shop 1','CC'),
('S2','Shop 2','XX'),
('S2','Shop 2','YY');
select
count(*) as [Activity],
[ID Code],
[ID Name],
[Shop Code]
from (
select
[ID Code],
[ID Name],
case when count(*) over (partition by [ID Code], [ID Name]) < 6 then 'Other Shop' else Shop end as [Shop Code]
from #ShopTable
) Q
group by [ID Code], [ID Name], [Shop Code];