Error in nested case query using SQL - mysql

Question

Trying to convert below query into SQL, query works fine on MySQL. Problem seems to be the CASE WHEN area field I get same error.
show Msg 102, Level 15, State 1, Line 44 Incorrect syntax near '='.
Msg 156, Level 15, State 1, Line 47 Incorrect syntax near the keyword
'AND'. Msg 156, Level 15, State 1, Line 49 Incorrect syntax near the
keyword 'ELSE'.
WHEN T.[StatusID] = 3
THEN
CASE WHEN (((SELECT COUNT(TA1.[Approver_ID]) FROM [QESTORM].[dbo].[CR_TicketApproval] TA1
INNER JOIN [QESTORM].[dbo].[CR_ControlFlow_SubRoute] CFSR1 ON TA1.[SubRoute_ID] = CFSR1.[ID]
WHERE TA1.[Ticket_ID]= #iTkID AND TA1.Active=1 AND CFSR1.Active=1 AND CFSR1.[Sequence] =(SELECT CFSR2.[Sequence] FROM [QESTORM].[dbo].[CR_Ticket] T2 INNER JOIN [QESTORM].[dbo].[CR_ControlFlow_SubRoute] CFSR2 ON T2.[SubRouteID] = CFSR2.[ID]
WHERE T2.[ID] = #iTkID))<(SELECT COUNT(DISTINCT CFSR1.[ID])FROM [QESTORM].[dbo].[CR_Ticket] AS T1 INNER JOIN [QESTORM].[dbo].[CR_ControlFlow_Route] AS CFR1 ON T1.[FormID] = CFR1.[FormID] INNER JOIN [QESTORM].[dbo].[CR_ControlFlow_SubRoute] AS CFSR1 ON CFR1.[ID] = CFSR1.[RouteID]
WHERE CFR1.[Active] = 1 AND CFSR1.[Active] = 1 AND T1.[ID] = #iTkID AND CFSR1.[Category] = 1 AND CFSR1.[Sequence] = ( SELECT CFSR2.[Sequence] FROM [QESTORM].[dbo].[CR_Ticket] AS T2 INNER JOIN [QESTORM].[dbo].[CR_ControlFlow_SubRoute] AS CFSR2 ON T2.[SubRouteID] = CFSR2.[ID]
WHERE T2.[ID] = #iTkID))))
THEN
CASE WHEN ((SELECT COUNT(1) FROM [QESTORM].[dbo].[CR_TicketApproval] WHERE [Ticket_ID]=#iTkID And [Active]=1) = 0)
THEN
--ERROR SHOW HERE => ((T.[AuditUser_ID] = '444' OR T.[AuditUser_ID] IS NULL) AND (nx.actor = 2 OR appSameSeq.NTLogin=in_NTLogin)
AND nx.actor=3
AND srSameSeq.subRouteID NOT IN (SELECT subRouteID FROM [QESTORM].[dbo].[CR_TicketApproval] WHERE [Ticket_ID]=#iTkID AND Active=1 )
AND appSameSeq.NTLogin=in_NTLogin
AND nx.actor=3 AND srSameSeq.subRouteID NOT IN (SELECT subRouteID FROM [QESTORM].[dbo].[CR_TicketApproval] WHERE [Ticket_ID] = #iTkID AND Active = 1)
ELSE 0
END

Answer 1

I'll toss my hat in the ring.
There may be more than one thing wrong with that SQL statement. What I'll point out is this:
CASE WHEN ((SELECT COUNT(1) FROM [QESTORM].[dbo]. [CR_TicketApproval] WHERE [Ticket_ID]=#iTkID And [Active]=1) = 0)
THEN
--ERROR SHOW HERE => ((T.[AuditUser_ID] = '444' OR T.[AuditUser_ID] IS NULL) AND (nx.actor = 2 OR appSameSeq.NTLogin=in_NTLogin)
AND nx.actor=3
AND srSameSeq.subRouteID NOT IN (SELECT subRouteID FROM [QESTORM].[dbo].[CR_TicketApproval] WHERE [Ticket_ID]=#iTkID AND Active=1 )
AND appSameSeq.NTLogin=in_NTLogin
AND nx.actor=3 AND srSameSeq.subRouteID NOT IN (SELECT subRouteID FROM [QESTORM].[dbo].[CR_TicketApproval] WHERE [Ticket_ID] = #iTkID AND Active = 1)
ELSE 0
END
Are you trying to evaluate a conditional expression, and return the result as a 1 or 0, as if it were a Boolean expression in a programming language?
That doesn't work in TSQL. This kind of expression evaluation:
SET #value = (1 > 0)
... will produce an error. You can't evaluate a conditional expression: you can only use it in a test, like in a WHERE, HAVING, or WHEN clause.
So, if that's what you're doing, you might do better to wrap your conditional evaluation in yet another CASE statement, like this:
THEN
CASE WHEN {complex conditional statement}
THEN 1
ELSE 0
END
ELSE
0
END
One other thing: this is an extremely complex query statement! I haven't analyzed it enough to see whether it could be simplified, but I'd suggest that you do so, with an eye toward using Common Table Expressions in place of some of your subqueries. This can make the query a lot easier to understand (and debug).

Answer 2

We are missing the complete query but it looks like you are opening too many parentheses.
If you look at the line where your error is shown:
((T.[AuditUser_ID] = '444' OR T.[AuditUser_ID] IS NULL) AND (nx.actor = 2 OR appSameSeq.NTLogin=in_NTLogin)
You are opening 2 parentheses but only close one.
That is why you get the error near else because you need to close that second parentheses before you can have an else
So you would need either
((T.[AuditUser_ID] = '444' OR T.[AuditUser_ID] IS NULL) AND (nx.actor = 2 OR appSameSeq.NTLogin=in_NTLogin))
or
(T.[AuditUser_ID] = '444' OR T.[AuditUser_ID] IS NULL) AND (nx.actor = 2 OR appSameSeq.NTLogin=in_NTLogin)
on that line

Answer 3

It looks like you don't have a 'return value' for your case statement on that specific line.
When you flatten your CASE WHEN statement you have something like this:
CASE WHEN <something> THEN
CASE WHEN <something else> THEN
CASE WHEN <something else again> THEN
-- THEN WHAT ?
ELSE
0
END
END
END
Instead of putting a value on the --THEN WHAT spot, you put another conditional statement. You have to select a value here.