sql - How To add composite unique key to user defined table Type -

how add composite unique key user defined table type :

create type [dbo].[jobdata] table(     [emp_num] [smallint] null,     [job_date] [date] null,     [year] [smallint] null,     [job_code] [smallint] null,     [order_year] [smallint] null,     [order_ser] [decimal](5, 0) null,  ) go 

i want emp_num,job_date composite unique key .

you can't alter userdefined table types ,you need drop , recreate again changes..

from msdn..

user-defined types cannot modified after created, because changes invalidate data in tables or indexes. modify type, must either drop type , re-create it, or issue alter assembly statement using unchecked data clause.

below way create unique constraint on userdefined table type

create type test table  ( col1 varchar(50) , col2 int ,  unique (col1,col2) ); 

note:we can't name constraints,so creating constraints normal way not valid..

example below

 create type test table      ( col1 varchar(50)     , col2 int ,     constraint test  unique (col1,col2)     );