Editing SQL User-Defined Data Types
To create or edit data types from the SQL Tables form, click and then:
- Select .
 - Specify the name, base data type, length and precision (if applicable for your base data type) and nullability
 - Save the record.
 - 
            Optionally, to change a data type, SQL Server requires that the 
	 data type be dropped and recreated. To drop a data type, it must not 
	 be in use by a table, stored procedure, or function. Perform these 
	 steps: 
	
            
- Filter for the data type and verify that the Where Type Used grid is empty.
 - Select and save the record to drop the data type.
 - Select , specify the information again, and save the data type record to recreate it.