can you do an ELSE WHEN on a CASE - sql

Question

CASE WHEN P.NURSING_UNIT is not null THEN P.NURSING_UNIT ELSE '' END NURSING_UNIT
,CASE WHEN P.UNIT_CODE is not null THEN P.UNIT_CODE ELSE '' END UNIT_CODE,
CASE WHEN M.SIGN_DATE IS NOT NULL THEN 'COMPLETED' ELSE
WHEN M.SIGN_DATE IS NULL THEN 'UNCOMPLETED' AS ASSESSMENTS
error: because the sp is not compiling now. getting this error message:
Msg 156, Level 15, State 1, Procedure GET_SCHEDULE_ALL_DETAIL, Line 18
Incorrect syntax near the keyword 'WHEN'.
Msg 156, Level 15, State 1, Procedure GET_SCHEDULE_ALL_DETAIL, Line 25
Incorrect syntax near the keyword 'AND'.
----
USE [PRO]
GO
/****** Object: StoredProcedure [dbo].[GET_SCHEDULE_ALL_DETAIL] Script Date: 11/02/2011 14:14:50 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
alter PROC [dbo].[GET_SCHEDULE_ALL_DETAIL]
#FACILITYKEY varchar(1000),
#UNITSTR VARCHAR(100),
#FromDate datetime,
#ToDate datetime
AS
BEGIN
(SELECT S.FACILITY_KEY, S.PAT_NUMBER, S.A3A_DATE_USER, M.REFERENCE_DATE ,
RTRIM(P.LAST_NAME) + CASE WHEN RTRIM(P.FIRST_NAME) <> '' THEN ', '
ELSE ''
END + RTRIM(P.FIRST_NAME) PATIENT_NAME
,CASE WHEN P.NURSING_UNIT is not null THEN P.NURSING_UNIT ELSE '' END NURSING_UNIT
,CASE WHEN P.UNIT_CODE is not null THEN P.UNIT_CODE ELSE '' END UNIT_CODE,
CASE WHEN M.SIGN_DATE IS NOT NULL THEN 'COMPLETED' ELSE
WHEN M.SIGN_DATE IS NULL THEN 'UNCOMPLETED' AS ASSESSMENTS
FROM [PC].MDS_M_SCHEDULE S INNER JOIN OPTC.MD3_M_MAST M
ON S.PAT_NUMBER=M.PAT_NUMBER
LEFT JOIN OGEN.GEN_M_PATIENT_MAST P ON S.PAT_NUMBER = P.PAT_NUMBER
WHERE S.PAT_NUMBER=M.PAT_NUMBER AND M.REFERENCE_DATE < GETDATE()
AND S.A3A_DATE_USER BETWEEN #FromDate AND #ToDate
AND S.FACILITY_KEY IN (SELECT Value FROM dbo.ListToTable(#FACILITYKEY,','))
AND ( #UNITSTR IS NULL
OR #UNITSTR = ''
OR CHARINDEX(P.UNIT_CODE, #UNITSTR)% 2 = 1 ))
UNION ALL
(SELECT * FROM (
(SELECT S.FACILITY_KEY, S.PAT_NUMBER, S.A3A_DATE_USER, M.REFERENCE_DATE ,
RTRIM(P.LAST_NAME) + CASE WHEN RTRIM(P.FIRST_NAME) <> '' THEN ', '
ELSE ''
END + RTRIM(P.FIRST_NAME) PATIENT_NAME
,CASE WHEN P.NURSING_UNIT is not null THEN P.NURSING_UNIT ELSE '' END NURSING_UNIT
,CASE WHEN P.UNIT_CODE is not null THEN P.UNIT_CODE ELSE '' END UNIT_CODE, 'LATE' AS ASSESSMENTS
FROM [PC].MDS_M_SCHEDULE S INNER JOIN OPTC.MD3_M_MAST M
ON S.PAT_NUMBER=M.PAT_NUMBER
LEFT JOIN OGEN.GEN_M_PATIENT_MAST P ON S.PAT_NUMBER = P.PAT_NUMBER
WHERE M.REFERENCE_DATE < GETDATE() AND S.A3A_DATE_USER BETWEEN #FromDate AND #ToDate
AND ( #UNITSTR IS NULL
OR #UNITSTR = ''
OR CHARINDEX(P.UNIT_CODE, #UNITSTR)% 2 = 1 )
) --Started
UNION ALL
(SELECT S.FACILITY_KEY, S.PAT_NUMBER, S.A3A_DATE_USER, NULL AS REFERENCE_DATE,
RTRIM(P.LAST_NAME) + CASE WHEN RTRIM(P.FIRST_NAME) <> '' THEN ', '
ELSE ''
END + RTRIM(P.FIRST_NAME) PATIENT_NAME
,CASE WHEN P.NURSING_UNIT is not null THEN P.NURSING_UNIT ELSE '' END NURSING_UNIT
,CASE WHEN P.UNIT_CODE is not null THEN P.UNIT_CODE ELSE '' END UNIT_CODE, 'LATE' AS ASSESSMENTS
FROM [PC].MDS_M_SCHEDULE S INNER JOIN OPTC.MD3_M_MAST M
ON S.PAT_NUMBER=M.PAT_NUMBER
LEFT JOIN OGEN.GEN_M_PATIENT_MAST P ON S.PAT_NUMBER = P.PAT_NUMBER
WHERE S.PAT_NUMBER NOT IN (SELECT M.PAT_NUMBER FROM [PC].MD3_M_MAST M)
AND S.A3A_DATE_USER < GETDATE() AND S.A3A_DATE_USER BETWEEN #FromDate AND #ToDate
AND ( #UNITSTR IS NULL
OR #UNITSTR = ''
OR CHARINDEX(P.UNIT_CODE, #UNITSTR)% 2 = 1 )) --Not Started
) LATE
WHERE FACILITY_KEY IN (SELECT Value FROM dbo.ListToTable(#FACILITYKEY,',')))
END
GO

Answer 1

No, ELSE is a catch-all. In your example, it's not clear why you would want to include a condition in the ELSE clause, since you've already checked the logically opposite condition in the first WHEN expression.
However, more generally, you can nest CASE expressions, which would look something like this:
CASE
WHEN m.sign_date IS NOT NULL THEN 'COMPLETED'
ELSE
CASE WHEN m.start_date IS NOT NULL THEN 'IN PROGRESS' ELSE 'NOT STARTED' END
END

Answer 2

I think you can just remove that else before the when, and add an end before 'as assessments'
coalesce(P.NURSING_UNIT , '') NURSING_UNIT, -- you can use coalesce here too
coalesce(P.UNIT_CODE, '') UNIT_CODE,
CASE
WHEN M.SIGN_DATE IS NOT NULL THEN 'COMPLETED'
WHEN M.SIGN_DATE IS NULL THEN 'UNCOMPLETED' END AS ASSESSMENTS

Answer 3

Change this part:
CASE WHEN M.SIGN_DATE IS NOT NULL THEN 'COMPLETED' ELSE
WHEN M.SIGN_DATE IS NULL THEN 'UNCOMPLETED'
to
CASE WHEN M.SIGN_DATE IS NOT NULL THEN 'COMPLETED' ELSE 'UNCOMPLETED' END
There's no point in having if (true) { ...} else if (false) { ... }. Just make the else unconditional.

Answer 4

Standard SQL:
COALESCE(P.NURSING_UNIT, '') AS NURSING_UNIT,
COALESCE(P.UNIT_CODE, '') AS UNIT_CODE,
CASE
WHEN M.SIGN_DATE IS NULL THEN 'UNCOMPLETED'
ELSE 'COMPLETED'
END AS ASSESSMENTS
If your vendor provides a REPLACE() function:
COALESCE(P.NURSING_UNIT, '') AS NURSING_UNIT,
COALESCE(P.UNIT_CODE, '') AS UNIT_CODE,
COALESCE(REPLACE(M.SIGN_DATE, M.SIGN_DATE, 'COMPLETED'), 'UNCOMPLETED') AS ASSESSMENTS