Deleting or Dropping an Alias Data Type in SQL SERVER

Imagine you had created a custom data type for your database:

USE Northwind;
GO
CREATE TYPE NaturalNumber FROM int;
GO

If you don't need such a data type any more, to assist you with removing it, Transact-SQL provides thesp_droptype. Its syntax is:

sp_droptype [ @typename= ] 'type'

This procedure takes one argument as the name of the custom data type you want to delete. Here is an example of executing it:

sp_droptype NaturalNumber;
GO