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