Check records you have in both CUSTOMER and INVOICE tables. SELECT * FROM CUSTOMER; SELECT * FROM INVOICE ; Page 1 of 4 Tasks to do 1. Write a trigger named TRG_UPDATE_CUST_BALANCE to update the CUST_BALANCE in the CUSTOMER table when a new invoice is added in the INVOICE table. The value of the INV_AMOUNT column of the new invoice should be added to the respective customer's balance in the CUSTOMER table. Test the trigger by adding the following new invoice record in the INVOICE table. \[ \begin{array}{l} \text { INV_NUM }=8005 \\ \text { CUST_NUM }=1001 \\ \text { INV_DATE }=27-\text { Apr-2016 } \\ \text { INV_AMOUNT }=225.40 \end{array} \] It should add the INV_AMOUNT of 225.40 to the balance of the customer (CUST_NUM = 1001) in the CUSTOMER table