This is just an example of Oracle Database Function to show you how can we create and call it as an individual database function not related to any PL/SQL package. Later on, In shaa Allah, we will declare and implement it with it's related database functions in a new package called a trans_pkg.
Now, let's start the current task definition.
2- Update its maximum quantity in the transaction table.
RAISE_APPLICATION_ERROR is actually a procedure that lets you define both error number from -20,000 up to -20,999 and its customized message.
Oracle Database Function Call
e.g. WHEN-BUTTON-PRESSED Trigger or any appropriate trigger to execute the database function code.