Database EAV Pros/Cons and Alternatives

Question

I have been looking for a database solution to allow user defined fields and values (allowing an unlimited number). At first glance, EAV seemed like the right fit, but afte

Answer 1

Is there an alternative database method to allow user defined attributes/fields and values?

One alternative is to change the database schema based on user input: for example when the user wants a new field, then add a corresponding column to the database.