Please answer all the questions urgently! Part $1$: Consider the SaleCo Database ERD:

Create a stored procedure that takes a date as input and displays the number of invoices

issued after that date.

Write a stored function that returns the number of customers in a given area code.

Create a trigger that checks whether a new invoice line could be inserted for a product.

The trigger should read the quantity on hand of the product appearing in the new invoice

line and deduct from it the quantity ordered in the new invoice line and compare the result

to the product's minimum quantity on hand. The trigger should raise an error if the result

is less than the minimum quantity on hand. Use RAISE EXCEPTION.

Create a trigger to update the customer balance $($CUS$\_$Balance$)$ in the customer table

after inserting any new Line row $($selling a product with line units and line price$).$