sql - Create custom defined unique identifier -

i have table uniqueidentifier column. insert script looks :

insert [users] ([userid], [name], [surname]) values (newid(), 'somename', 'somesurname') 

newid() creates new guid, inserted table. create data defined id column, not automatically generated. e.g. 'a0000000-0000-0000-0000-000000000000'. code doesn't work because throws error 'string or binary data truncated.' :

insert [users] ([userid], [name], [surname]) values ('a0000000-0000-0000-0000-000000000000', 'somename', 'somesurname') 

i tried cast custom guid, not successful well.

insert [users] ([userid], [name], [surname]) values (cast('a0000000-0000-0000-0000-000000000000' uniqueidentifier), 'somename', 'somesurname') 

do have clue how can solve inserting data custom defined id?

you don't have cast it. sql server you.

this code works well:

create table x ( uniqueidentifier );  insert x values ('a0000000-0000-0000-0000-000000000000') ;  insert x values ('bbe46a77-3518-40e4-9b77-3275f3531b8b') ;  select * x ;