CODEWITHSUNDEEP
c#nhibernate
lexeme
lexeme

Reputation: 2973

When does ID get generated in NHibernate

What I want to know is when NHibernate assigns/generates a value to Id field. After an entity is saved into repository? I need to use a Product Id to build a compound filename. But when I do use an Id before saving entity into repository I get Guid.Empty.

Thanks!

Upvotes: 2

Views: 2202

Answers (2)

Ranu Mandan
Ranu Mandan

Reputation: 286

please see below link for your answer

http://nhibernate.info/doc/nh/en/index.html#mapping-declaration-id

"But when I do use an Id before saving entity into repository I get Guid.Empty" -> id will only be generated once record it saved into database... if you want id before then i would suggest using assigned id generator, where you can generate your id before your record in saved into db.

Upvotes: 0

Rippo
Rippo

Reputation: 22424

I am wondering why you need to use the Id before a save takes place? Surely using an Id after it has been successfully committed to the database is the correct approach. After all if you use the Id and then find the database has not persisted the entity then this will give you unwanted side effects.

However there is a work around but it is not very nice.

Set the id generator to assigned. This comes with some caveats, you cannot use SaveOrUpdate as NHibernate will not be able to detect that this is a new entity or one that needs updating. This means that you should either use the Save or Update methods explicitly

Upvotes: 4

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