Hi,

I am using MindTap on Cengage for my DAT 380 course. I need help with the following problems;

Problem 31

Create a trigger named trg_line_total to write the LINE_TOTAL value in the LINE table every time you add a new LINE row. (The LINE_TOTAL value is the product of the LINE_UNITS and LINE_PRICE values.)

Problem 33

Create a stored procedure named prc_inv_amounts to update the INV_SUBTOTAL, INV_TAX, and INV_TOTAL. The procedure takes the invoice number as a parameter. The INV_SUBTOTAL is the sum of the LINE_TOTAL amounts for the invoice, the INV_TAX is the product of the INV_SUBTOTAL and the tax rate (8 percent), and the INV_TOTAL is the sum of the INV_SUBTOTAL and the INV_TAX.

Problem 34

Create a procedure named prc_cus_balance_update that will take the invoice number as a parameter and update the customer balance.

(Hint: use the OLD keyword.)