What is the syntax for day of week select case? - sql

Question

I'm trying to use a case select if the day is Monday (or d is equal to 2), and the 'else' would handle every other day of the week.
Select to_char (sysdate, 'D') d from dual,
/*if 2 or Monday then run this part*/
CASE
2
Then
SELECT DISTINCT RPAD(CLAIM.CLAIM_NUMBER, 20) ||
LPAD(CLAIM.CLAIM_ID, 15, '0') ||
TO_CHAR(CLAIM.INCIDENT_DATE, 'MMDDYYYY') ||
LPAD(' ',2) ||
'D'
FROM CLAIM,CLAIMANT,INSURER,POLICY
WHERE CLAIM.CLAIM_ID = CLAIMANT.CLAIM_ID
AND POLICY.INSURER_NUMBER = INSURER.INSURER_NUMBER
AND INSURER.INSURER_NUMBER NOT IN ('7','8')
AND CLAIMANT.EXAMINER1_CODE NOT IN ('MAYCONV')
AND CLAIM.INSURANCE_TYPE = 2
AND CLAIM.JURISDICTION_CODE <> 1
AND CLAIMANT.CLAIMANT_TYPE_CODE in (4,7)
/*if Monday then go 2 days back*/
AND CLAIMANT.EDIT_DATE > (SYSDATE - 2)
/*if not equal to 2 or any day but Monday then run this part*/
Else
SELECT DISTINCT RPAD(CLAIM.CLAIM_NUMBER, 20) ||
LPAD(CLAIM.CLAIM_ID, 15, '0') ||
TO_CHAR(CLAIM.INCIDENT_DATE, 'MMDDYYYY') ||
LPAD(' ',2) ||
'D'
FROM CLAIM,CLAIMANT,INSURER,POLICY
WHERE CLAIM.CLAIM_ID = CLAIMANT.CLAIM_ID
AND POLICY.INSURER_NUMBER = INSURER.INSURER_NUMBER
AND INSURER.INSURER_NUMBER NOT IN ('7','8')
AND CLAIMANT.EXAMINER1_CODE NOT IN ('MAYCONV')
AND CLAIM.INSURANCE_TYPE = 2
AND CLAIM.JURISDICTION_CODE <> 1
AND CLAIMANT.CLAIMANT_TYPE_CODE in (4,7)
/*if not Monday then go 1 day back*/
AND CLAIMANT.EDIT_DATE > (SYSDATE - 1)
/

Answer 1

I didn't follow your code closely, but it seems you just want the last condition in your where clause to depend on the day of the week.
If so, you need something like (WARNING: I didn't check anything else in the code to make sure it is correct or efficient!) - the only change is in the last line. You don't need the select... from dual and you only need to write the select statement once.
SELECT DISTINCT RPAD(CLAIM.CLAIM_NUMBER, 20) ||
LPAD(CLAIM.CLAIM_ID, 15, '0') ||
TO_CHAR(CLAIM.INCIDENT_DATE, 'MMDDYYYY') ||
LPAD(' ',2) ||
'D'
FROM CLAIM,CLAIMANT,INSURER,POLICY
WHERE CLAIM.CLAIM_ID = CLAIMANT.CLAIM_ID
AND POLICY.INSURER_NUMBER = INSURER.INSURER_NUMBER
............
AND CLAIMANT.EDIT_DATE > SYSDATE - case to_char(sysdate, 'd') when 2 then 2 else 1 end