Inline Select Query

Question

i want to check the pending payments against the PurchaseOrder.
i wrote this query but got no rows returned.
SQL> SELECT (B.POHAMT-C.FTHAMT) NET
  2  FROM
  3  (
  4  SELECT NVL(POH_gross_lc_amount,0)-nvl(poh_comm_lc_amount,0)  POHAMT
  5  FROM  PURCHASE_ORDER_HEADER
  6  WHERE POH_NO = 5
  7  AND   POH_CODE = 'PUR') B,
  8  (
  9  SELECT SUM(NVL(FTH_LC_AMOUNT,0)) FTHAMT
10  FROM FIN_TXN_HEADER
11  WHERE FTH_REF_CODE = 'PUR'
12  AND FTH_REF_NO = 5
13  GROUP BY FTH_REF_CODE,FTH_REF_NO) C;
no rows selected
let me show you the break-up of the above query.
there is 1 record existing in the purchase order, for which the payment is yet to be made.
SQL> SELECT
  2  NVL(POH_gross_lc_amount,0)-nvl(poh_comm_lc_amount,0)  POHAMT
  3  FROM  PURCHASE_ORDER_HEADER
  4  WHERE POH_NO = 5
  5  AND   POH_CODE = 'PUR';
    POHAMT
       265
for the second part there is no payment exist for the poh_no 5, so no records returned, fair enough.
SQL> SELECT FTH_REF_CODE,FTH_REF_NO,SUM(NVL(FTH_LC_AMOUNT,0)) FTHAMT
  2  FROM FIN_TXN_HEADER
  3  WHERE FTH_REF_CODE = 'PUR'
  4  AND FTH_REF_NO = 5
  5  GROUP BY FTH_REF_CODE,FTH_REF_NO;
no rows selected
what the above query should do is, incase if there is no payment exist, then it should returned 265 for the Net column please help where am i wrong.

Answer 1

user613563 wrote:
i want to check the pending payments against the PurchaseOrder.
i wrote this query but got no rows returned.
SQL> SELECT (B.POHAMT-C.FTHAMT) NET
2  FROM
3  (
4  SELECT NVL(POH_gross_lc_amount,0)-nvl(poh_comm_lc_amount,0)  POHAMT
5  FROM  PURCHASE_ORDER_HEADER
6  WHERE POH_NO = 5
7  AND   POH_CODE = 'PUR') B,
8  (
9  SELECT SUM(NVL(FTH_LC_AMOUNT,0)) FTHAMT
10  FROM FIN_TXN_HEADER
11  WHERE FTH_REF_CODE = 'PUR'
12  AND FTH_REF_NO = 5
13  GROUP BY FTH_REF_CODE,FTH_REF_NO) C;
no rows selectedplease help where am i wrong.Not sure if I got everything right. Main problem is to create a row first. Then you can work with NVL.
One way could be to outer join the two queries.
untested
SELECT nvl(c.FTH_REF_CODE,'HEADER'), c.FTH_REF_NO, NVL(C.FTHAMT,B.POHAMT) NET
FROM
       (SELECT 1 dummy, NVL(POH_gross_lc_amount,0)-nvl(poh_comm_lc_amount,0)  POHAMT
        FROM  PURCHASE_ORDER_HEADER
       WHERE POH_NO = 5
       AND   POH_CODE = 'PUR') B
LEFT OUTER JOIN
        (SELECT 1 dummy, SUM(NVL(FTH_LC_AMOUNT,0)) FTHAMT, FTH_REF_CODE,FTH_REF_NO
         FROM FIN_TXN_HEADER
         WHERE FTH_REF_CODE = 'PUR'
         AND FTH_REF_NO = 5
         GROUP BY FTH_REF_CODE,FTH_REF_NO) C
ON b.dummy = c.dummy