Question

Maybe this is simpler and more straightforward then what I’m thinking but I can’t seem to find this concept on google anywhere. The concept is this:

You have a table in a database and the table has a specified number of columns. However, it has been asked of me by previous clients that there also be a set of dynamic user defined columns that can be added on the fly.

What is this concept called and is it considered a design pattern?

Answer 1

You’re probably talking about name-value pairs.

Like this:

UserProfile
-----------
UserID  PropertyName  PropertyValue

But it doesn’t mean you add columns to a table dynamically. It’s not done this way.

Officially it is known as the Entity-attribute-value model.