use oracle sql command line with found or notfound method

table customer(customerNo, customerName , gender)

with trigger like this one it may has some errors

create or replace trigger increment_id

before insert on table_name

for each row

Begin

select max(table_id)+1 into :new.table_id from table_name;

End ;

4) Create database package pointOfSal which contain the following A. procedure to add new customer which use validation method checkExistingCustomer using cursor to validate customer name if its not exists before, then add this new customer and generate the customer number automatically using database trigger