Hello all,

the documentation states that:

"It's not necessary to define a unique constraint for foreign key fields participating in a 1:1 relationship: LLBLGen Pro creates these unique constraints in the Relational Model Data automatically for you. Any unique constraint defined over the same fields is therefore redundant."

My question is: is there a way to disable the generation of these unique constraints (in the SQL scripts and mapping files) within the LLBLGen designer?

Thank you, Stefan

No, as it would make it possible to insert the same FK value twice, which makes it no longer a 1:1 relationship. You can of course model the relationship as 'model-only' (so it doesn't have a backing FK+UC)

Could you elaborate a bit why you'd need this? I.e.: why you'd need a 1:1 relationship while there's no UC on the FK?

Thanks for the quick reply.

It's actually a 1:0..1 (UserAccount:Language) relationship, where the foreign key field has to be nullable (in case there is no matching entity of type Language for a particular entity of type UserAccount).

I'm getting a unique constraint violation error while inserting two UserAccounts that have no matching Language:

"Cannot insert duplicate key in object 'dbo.UserAccount'. The duplicate key value is (<NULL>)."

I've tried making the relationship Model-only but then the foreign key constraint isn't generated either (makes sense).

I'm using NHibernate and MS SQL Server.

Thanks again.

I've tried making the relationship Model-only but then the foreign key constraint isn't generated either (makes sense).

That's the only way as I see it. You mark the relation as model-only. Then you define the FK in the database. Subsequent UPDATE scripts shouldn't remove the FK, if I'm not missing anything.

Thanks for clarifying it, much appreciated.

Cheers, Stefan