In my org I have some users logged in as normal Salesforce User. The project is a typical e-commerce with a object called product , and, I want to create a ShoppingCart Object for each user (otherwise every user can view the records in the ShoppingCart Object). I don't know if is possibile, exist a method to automate the creation of that obj when a new User signs up in my org? Or I should to use session methods in my code? I hope my question is clear, thanks in advance

I have a list of records from Object 1, every record has a command link named "Buy" and i want copy the record choosed in Object 2. I've tried to build this with apex code without success. I should create a Master Detail rel but I can't understand how to do that in my specific case. Can you explain  how to copy records from a Object to another with the use of commandLinks?

I have 2 object:
Products and Cart. The objects have the same fields.
I want to copy after a click (in a commandlink in my products vfp) a product from the Object products in a Cart object.
How i can write the code?

I need to use a triggers to check if the last letter of a fiscal code (In my country correspond with the birthtown of a person) is equal with the country...how can I make it?

Can someone help me with this formula? I need to check if a date field is between 2 dates fields.

"check that the date of performance is between the start and end date of the policy." Thanks in advance