Is it possible to overide null statement in the following sql. Note the field in SPCL_EARNS cannot contain a null value.
SET X.SPCL_EARNS =
FROM PS_CAAT_TMP TMP
LEFT OUTER JOIN PS_SPCL_EARNS SPCL
ON SPCL.PAGE_NUM = TMP.PAGE_NUM
AND SPCL.LINE_NUM = TMP.LINE_NUM
AND SPCL.SEPCHK = TMP.SEPCHK
AND SPCL.OFF_CYCLE = TMP.OFF_CYCLE
AND SPCL.PAY_END_DT = TMP.PAY_END_DT
AND SPCL.EMPL_RCD = TMP.EMPL_RCD
AND SPCL.PAYGROUP = TMP.PAYGROUP
WHERE SPCL.PAY_END_DT >= CASE WHEN X.MAX_PENS_EFFDT >= '01-01-2013' THEN X.MAX_PENS_EFFDT ELSE '01-01-2013' END
AND SPCL.PAY_END_DT <= '03-23-2013'
AND TMP.EMPLID = X.EMPLID
AND TMP.EMPL_RCD = X.EMPL_RCD
group by TMP.EMPLID, TMP.EMPL_RCD)
FROM PS_PY_CAAT_CALC X
Any assistance would be greatly appreciated. I don't know how to encase this statement in a case statement.