Question

1. Table1: customers

   cust_no | cust_credbal | cred_status

2. Table2:customer_credittopup

   cust_no | trans_amount

I have the above two tables, I have written an update trigger after insert into the Table2 to update Table1. Thus the amount in Table1 cust_credbal is updated after adding cust_credbal in Tabl1 + the new value in trans_amount in Table2. How do i add an if statement after the update to check if cust_credbal is > than 20 then cred_status is is set to ‘VALID’ else ‘EXHAUSTED’

My trigger showing this error: Error at line 8: PLS-00049: bad bind variable ‘NEW.CUST_CREDITBAL’

CREATE OR REPLACE TRIGGER after_insert_credittopup
AFTER INSERT ON customer_credittopup
FOR EACH ROW 
DECLARE 
  credit number(11);
BEGIN
  UPDATE customers
     SET cust_creditbal=cust_creditbal +:new.trans_amount
   WHERE cust_no=:new.cust_no;

  SELECT Cust_creditbal INTO credit 
    FROM customers WHERE cust_no=:new.cust_no;

  IF(:new.cust_creditbal>0) THEN
    UPDATE customers
       SET Cust_credstatus='Valid'
     WHERE cust_no=:new.cust_no;
  end if;
end;
/

Answer 1

It seems that all you need here is just 1 update statement :

UPDATE customers
SET cust_creditbal=cust_creditbal +:new.trans_amount,
Cust_credstatus = CASE WHEN cust_creditbal +:new.trans_amount > 0 THEN 'Valid'
 ELSE 'Invalid' 
 --or if you don't want to change status in such case just put 
 --ELSE Cust_credstatus 
 END
 WHERE cust_no=:new.cust_no;
 --SELECT Cust_creditbal INTO credit FROM customers WHERE cust_no=:new.cust_no;
 --IF(:new.cust_creditbal>0) THEN
 --UPDATE customers
 --SET Cust_credstatus='Valid'
 --WHERE cust_no=:new.cust_no;