Ayende @ Rahien

Ayende Rahien commented on NHibernate Mapping -

Thu, 04 Jun 2009 11:21:54 GMT

Yes, it is.

Umair commented on NHibernate Mapping -

Wed, 03 Jun 2009 23:18:01 GMT

In your post you mentioned, "if I wanted to use the

Frans Bouma commented on NHibernate Mapping -

Wed, 03 Jun 2009 09:51:04 GMT

@Ayende: agreed, I overlooked the where clauses in the UPDATE statements.

DaRage commented on NHibernate Mapping -

Tue, 02 Jun 2009 14:39:43 GMT

Hi Guys, Again regarding the left join. I still don't understand. I was assuming if the foreign key is nullable (ie the phoneId in UserToEmergencyPhones table) than the query will be left join. but if the phoneId column is not nullable it will an inner joint. Or does NHibernate assumes that there will be orphane phoneIds and do a left join all the time. doesn't orphane phone ids mean data corruption and should be protected against by using foreign keys?

Ayende Rahien commented on NHibernate Mapping -

Tue, 02 Jun 2009 11:35:49 GMT

Frans, Nope, it doesn't. If two threads are messing with it, one of them is going to get a concurrency violation error, as expected.

Tigraine commented on NHibernate Mapping -

Tue, 02 Jun 2009 11:32:50 GMT

Thanks for the reply Ayende. I'll look into the ordered set..

Frans Bouma commented on NHibernate Mapping -

Tue, 02 Jun 2009 11:25:17 GMT

This only works if there's just 1 thread of the app modifying the position parameter. I.o.w.: a table lock is required. I don't see that as a valuable feature, if people have to maintain the index anyway, they can also add a position property to the entity and be done with it.

Ayende Rahien commented on NHibernate Mapping -

Tue, 02 Jun 2009 10:28:07 GMT

Tigraine, Because in general, having NH doing something like that for you can be bad. There is a _meaning_ to null values. But broadly, it is because it is not the responsibility of NHibernate to do so. If you want something like that, you don't need a list, you need an ordered set. As for the second thing, ordering is for a single collection. You can have polymorphic association using list, however.

Tigraine commented on NHibernate Mapping -

Tue, 02 Jun 2009 10:21:46 GMT

Thanks for the article. Very interesting. I just wonder why there is no "figure it out" property in the mappings. Something that instructs NH to also fix the missing indexes (resulting in more work for the DB but saving the developer some trouble). Also is there a way to persist two collections with the same ordering? Like OrderLineItems and OrderLineText, both maybe deriving from the same base but being different... (I had two lists on the Order, which I could mix to their common base but kept seperated for some calculations) greetings Daniel

Ayende Rahien commented on NHibernate Mapping -

Tue, 02 Jun 2009 09:51:20 GMT

Try build 294, it is there, when you select multiple statements.

Krzysztof Kozmic commented on NHibernate Mapping -

Tue, 02 Jun 2009 08:13:21 GMT

when did you add the --statement #x My build does not have it yet ;)

Eric Hauser commented on NHibernate Mapping -

Tue, 02 Jun 2009 03:05:42 GMT

Hibernate returns null for a missing entry as well.

DaRage commented on NHibernate Mapping -

Tue, 02 Jun 2009 01:37:07 GMT

I didn't understand why in the second query, UserToEmergencyPhones is left joined to the Phones table. Shouldn't it be an inner join?