SQLce create table "index field" explanation (SQL Management Studio)?

I'm new to databases, and now creating SQLCE database in Management Studio. There is a value in brackets; [UQ_Users_0000000000000028], which seems a bit random to me, so would just like to ask if someone could explain this field?

Is it just simply required to be a unique field? Is there any reason why I would want to change it to something else than what SSMS scripts?

cheers!

C开发者_Go百科REATE TABLE [Users] (
  [UserID] int NOT NULL
.....
CREATE UNIQUE INDEX [UQ__Users__0000000000000028] ON [Users] ([UserID] ASC);

Yes, I'd recommend changing it's name to make some kind of sense (useful when querying the system views), for example UQ_Users_UserID.

This was probably originally created with something like :-

CREATE TABLE [Users] ( [UserID] int UNIQUE NONCLUSTERED, .....

so SQL Server will have assigned it it's own (non-helpful) constraint name.

They are default constraint names designed to provide uniqueness across servers. I always name mine to avoid scripting issues.