Return a 0 when no data present - ssms

Question

I have looked at a few questions similar and tried to apply my own knowledge to get the query to work correctly but still cant get the outcome i desire.
I have 5 Call lines i need to report on from our DB. The problem is some of them can go a full day without a call. Instead of reporting 0, it just doesn't pull the line through. Unfortunately for Reporting purposes I need it to put 0.
SELECT CASE [Campaign]
WHEN '1' THEN 'Line A'
WHEN '2' THEN 'Line B'
WHEN '3' THEN 'Line C'
WHEN '4' THEN 'Line D'
WHEN '5' THEN 'Line E'
ELSE 'Outbound Dialling' END AS [Line_name],
COUNT(UniqueID) AS [Total Calls]
FROM Telephone_Table
WHERE [CallTime] BETWEEN '2017-12-01 00:00:00' AND '2017-12-01 23:59:59'
AND [Campaign] IN ('402','403','404','405','406')
Result:
Line_name | Campaign | Total Calls
Line A | 402 | 13
Line B | 403 | 11
Line C | 405 | 26
Line E | 406 | 178
Quite often Line D doesn't get a call. Instead of listing it as 0 it will miss it completely.
I have tried the following but none have worked:
COUNT(UniqueID)+1
CASE WHEN COUNT(UniqueID) = '0' THEN 1 ELSE COUNT(UniqueID)
I tried creating another table in the DB with just these lines and a name in there to join against instead of using a "Case When" in case that was the issue but that didn't work.
Any one have any suggestions? Thank you.

Answer 1

Here's a suggestion: add a dummy for each group you want displayed, then subtract 1 from the count:
SELECT CASE [Campaign]
WHEN '402' THEN 'Line A'
WHEN '403' THEN 'Line B'
WHEN '404' THEN 'Line C'
WHEN '405' THEN 'Line D'
WHEN '406' THEN 'Line E'
ELSE 'Outbound Dialling' END AS [Line_name]
,[Campaign]
,COUNT(UniqueID)-1 AS [Total Calls]
FROM
(SELECT [Campaign], [UniqueID] FROM Telephone_Table
WHERE [CallTime] BETWEEN '2017-12-01 00:00:00' AND '2017-12-01 23:59:59'
AND [Campaign] IN ('402','403','404','405','406')
UNION SELECT '402' AS [Campaign], 'DUMMY1' AS UniqueID
UNION SELECT '403' AS [Campaign], 'DUMMY2' AS UniqueID
UNION SELECT '404' AS [Campaign], 'DUMMY3' AS UniqueID
UNION SELECT '405' AS [Campaign], 'DUMMY4' AS UniqueID
UNION SELECT '406' AS [Campaign], 'DUMMY5' AS UniqueID) AS a
GROUP BY [Campaign]
I may have mixed up my syntax, I don't have sql-server handy at the moment to check, but this general idea should work.