SQL Server/T-SQL Tutorial/System Functions/sp addtype
execute sp_addtype id,"varchar(11)" ,"NOT NULL"
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execute sp_addtype id ,"varchar(11)" ,"NOT NULL" GO</source>
sp_addtype creates your own specific datatypes, including how the SQL Server will handle NULL values.
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sp_addtype typename, SQLtype[,NULLhandler] sp_addtype HireDate,datetime,"NOT NULL"</source>
User-Defined Datatypes
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29> 30> sp_addtype ssn, "varchar(11)", "NOT NULL" 31></source>