關於CASE WHEN ... THEN ... END的SQL使用例子

SELECT A.ORG_ID, A.SALES_ID, A.SALES_TYPE, A.INV_DATE, A.INVOICE_NO, A.INV_TYPE, A.TAX_KIND,A.PAY_CUSTID, A.MONEY_UNIT, A.PAY_NO,A.AR_PERIOD,A.PL_AR_DATE, A.CLAIM_NO,A.STATUS, A.SALES_NO, A.SALES_DATE, A.SE_ID, A.PO, A.OTYPE,
(CASE WHEN (B.PAY_TYPE=1 AND ARDAY_NUM > TO_CHAR(INV_DATE,'DD') )
THEN TO_DATE(TO_CHAR(INV_DATE,'YYYYMM')||LPAD(ARDAY_NUM,2,'0'),'YYYY/MM/DD')
ELSE CASE WHEN (B.PAY_TYPE=1 AND ARDAY_NUM<= TO_CHAR(INV_DATE,'DD') )
THEN ADD_MONTHS(TO_DATE(TO_CHAR(INV_DATE,'YYYYMM')||LPAD(ARDAY_NUM,2,'0'),'YYYY/MM/DD'),1)
ELSE CASE WHEN (B.PAY_TYPE=2)
THEN TRUNC(NEXT_DAY(INV_DATE,ARDAY_NUM+1))
END
END
END ) AR_DATE,
SUM(QTY)QTY, SUM(NET_MONEY) MONEY
FROM VW_AR_SALES A, CR_CUST_AR B
WHERE A.SALES_TYPE=1
AND A.STATUS =2
AND A.REQ_MARK='Y'
AND A.AR_ID IS NULL
AND A.ORG_ID=B.ORG_ID
AND A.PAY_CUSTID=B.CUST_ID
AND B.O_TYPE= A.OTYPE
GROUP BY A.ORG_ID, A.SALES_ID, A.SALES_TYPE, A.INV_DATE, A.INVOICE_NO, A.INV_TYPE, A.TAX_KIND,A.PAY_CUSTID, A.MONEY_UNIT,
A.PAY_NO,A.AR_PERIOD,A.PL_AR_DATE, A.CLAIM_NO,A.STATUS, A.SALES_NO,A.SALES_DATE, A.SE_ID, A.PO, A.OTYPE,A.UNIT_PRICE,A.MONEY,B.PAY_TYPE,ARDAY_NUM