case in where clause causes the error : An expression of non-boolean type specified in a context where a condition is expected, near ')'

Question

I'm getting the below error message when I compile the query:

Error : An expression of non-boolean type specified in a context where a condition is expected, near ')'.

Query:

Select * from EPLMethods SP WHERE EPLMEthodId=@EplMethodId
AND
                    (
                        CASE  WHEN (ISNULL(SP.Data.value('(/*/subject)[1]', 'bit'), 0)= 1 AND ISNULL(SP.Data.value('(/*/answers)[1]', 'nvarchar(max)'), '') = '')                                               

                             THEN 1

                        ELSE 
                                 Case WHEN (SELECT COUNT (*) FROM dbo.GetEPLData3(@EplMethodId, 1, SP.Data.value('(/*/Answers/AnswersList/Entry[@key="number"]/value)[1]', 'nvarchar(max)')))> 0 Then
                                 1 
                                 ELSE
                                 0
                                 END
                        END
                    )

Answer 1

Just add = 1 behind the CASE 's closing END .

Select * from EPLMethods SP WHERE EPLMEthodId=@EplMethodId
AND
                    (
                        CASE  WHEN (ISNULL(SP.Data.value('(/*/subject)[1]', 'bit'), 0)= 1 AND ISNULL(SP.Data.value('(/*/answers)[1]', 'nvarchar(max)'), '') = '')                                               

                             THEN 1

                        ELSE 
                                 Case WHEN (SELECT COUNT (*) FROM dbo.GetEPLData3(@EplMethodId, 1, SP.Data.value('(/*/Answers/AnswersList/Entry[@key="number"]/value)[1]', 'nvarchar(max)')))> 0 Then
                                 1 
                                 ELSE
                                 0
                                 END
                        END
                        = 1
                    )

As the error states, you're trying to use a number where the SQL Server expects a boolean - unlike some other languages, there is no implicit conversion from number to logical value in SQL Server, so you have to convert it yourself.

SQL Fiddle .