Mutating Table values

Question

I am facing problem when i have to insert more than 2 records to a certain table where in 1 record i have suppose RS 10 debit amount, against that i enetered 2 records thro' form ,i have to write trigger which will fire is the credit amounts which r to be entered against that debit amount should matched..but when i can't make group by in trigger since i required some values which r to be supplied to cursor..& it will possible only if i write for each row..but for each row i will not be able to group by .. the code is
CREATE OR REPLACE TRIGGER FAS.&TRIGGER_NAME
BEFORE INSERT
ON &TABLE_NAME
REFERENCING NEW AS NEW OLD AS OLD
FOR EACH ROW
DECLARE
CURSOR CUR_DB_CR IS
     SELECT SUM(TR_ACCT_AMT),ACCT_AMT_DCIND
     FROM &TABLE_NAME
     WHERE COMPANY_CD = :NEW.company_cd
     AND PERIOD_CD = :NEW.period_cd
     AND TR_CD = :NEW.tr_cd
     AND DOC_NO = :NEW.doc_no
     AND DOC_DT = :NEW.doc_dt
     GROUP BY ACCT_AMT_DCIND ;
lv_DB_TR_ACCT_AMT NUMBER ;
lv_CR_TR_ACCT_AMT NUMBER ;
lv_TR_ACCT_AMT NUMBER;
lv_ACCT_AMT_DCIND VARCHAR2(1);
BEGIN
OPEN CUR_DB_CR ;
LOOP
FETCH CUR_DB_CR INTO lv_TR_ACCT_AMT,lv_ACCT_AMT_DCIND ;
EXIT WHEN CUR_DB_CR%NOTFOUND ;
IF lv_ACCT_AMT_DCIND = 'D' THEN
     lv_DB_TR_ACCT_AMT := lv_TR_ACCT_AMT;
END IF ;
IF lv_ACCT_AMT_DCIND = 'C' THEN
     lv_CR_TR_ACCT_AMT := lv_TR_ACCT_AMT;
END IF ;
END LOOP ;
-- IF CUR_DB_CR%ROWCOUNT >= 2 THEN     
IF lv_DB_TR_ACCT_AMT <> lv_CR_TR_ACCT_AMT THEN
     RAISE_APPLICATION_ERROR(-20055,'*START* Can Not INSERT..DEBIT CREDIT AMOUNT MISMATCH...! END');
END IF ;
-- END IF;
CLOSE CUR_DB_CR;
END ;

Answer 1

The Mutating Table problem is tricky and difficult. First of all, I would ask for help on the database form rather than here.
If you want your trigger to access and update other rows in the same table when you update or insert a row, you need to create several triggers, and they need to store and access data in a database package. There are some pointers on the Ask Tom website within Oracle.
Good luck.