Ayende @ Rahien

Ayende Rahien commented on NHibernate Mapping -

Thu, 16 Apr 2009 08:20:06 GMT

Anatoly, Wait a few days, the post about {join/} will show up

tolly commented on NHibernate Mapping -

Thu, 16 Apr 2009 08:13:42 GMT

Thanks, Ayende, it works :-) I have added IDictionary Properties to my Question class to map key-value pairs. My mapping looks like this: {map name="Properties" table="QuestionDetails" } {key column="QuestionID" /} {index column="Name" type="String" /} {element column="Value" type="String" /} {/map} How can i force NHibernate to use this mapping if I create new QuestionType (subclass) object? Now create a Question object as follows: Question sbq = new Question(); sbq.attr1= "attr1value"; sbq.attr2= "attr2value"; sbq.Properties = new Dictionary (); sbq.Properties.Add( "attr3", "attr3" ); sbq.Properties.Add( "attr4", "attr4" ); And I'd like to have it so: QuestionType2 sbq = new QuestionType2 (); sbq.attr1= "attr1value"; sbq.attr2= "attr2value"; sbq.attr2= "attr3value"; sbq.attr2= "attr4value"; Should I use discriminator? Or

Ayende Rahien commented on NHibernate Mapping -

Wed, 15 Apr 2009 19:50:43 GMT

Tolly, Take a look at {map/}

tolly commented on NHibernate Mapping -

Wed, 15 Apr 2009 15:43:03 GMT

How can i solve this (see picture) problem with NHibernate? i have a superclass Question and a lot of subclasses, all with their own specific attributes. I don't want to create table for each class, because of perfomance. The solution is to make an QuestionDetail table with key, value columns where i can store names and values of all specific attributes from subclasses. How can i do it in NHibernate? [tweakers.net/.../full.jpg](http://tweakers.net/ext/f/iXzIAjRLJRji3MYD1rCoZk0J/full.jpg)

CAM commented on NHibernate Mapping -

Wed, 15 Apr 2009 13:51:43 GMT

Excellent Ayende thank you.

Ayende Rahien commented on NHibernate Mapping -

Wed, 15 Apr 2009 13:28:15 GMT

CAM, Take a look at the {map/} element

CAM commented on NHibernate Mapping -

Wed, 15 Apr 2009 12:57:56 GMT

Sorry Ayende, I was referring to Mike's comment. Could you show an example of how to map a property bag table (Name/Value Pair) in DB to an IDictionary Attributes property of a class?

Ayende Rahien commented on NHibernate Mapping -

Wed, 15 Apr 2009 11:41:31 GMT

CAM, Attributes is IDisctionary

CAM commented on NHibernate Mapping -

Wed, 15 Apr 2009 11:39:50 GMT

Excellent stuff, a question on using an Attributes table comment. How would you make the Attributes property a simple dictionary?

meowth commented on NHibernate Mapping -

Mon, 13 Apr 2009 07:12:06 GMT

Hrr. I had to use Boo compiler to regenerate entities on-the-fly when adding fields instead of simply using dynamic component.. Thank you for this set of lectures about NHibernate features, Ayende.

Ayende Rahien commented on NHibernate Mapping -

Sun, 12 Apr 2009 02:58:19 GMT

Mike, you can create an Attributes table very easily, and map it using standard NH facilities. That tend to be slower, however, because you need an additional select or a join.

Mike commented on NHibernate Mapping -

Sun, 12 Apr 2009 02:16:14 GMT

Putting some data in the xml document about your mapping doesn't seem very dynamic to me. nor does adding a column to the database. Is there anyway you could show an example that uses a property bag in both the database and object model?

Ayende Rahien commented on NHibernate Mapping -

Sat, 11 Apr 2009 18:06:18 GMT

Justin, You usually would do this by manipulating the mapping problematically.

justin commented on NHibernate Mapping -

Sat, 11 Apr 2009 16:40:31 GMT

I guess my question would be _how_ do you dynamically extend the entity? Putting some data in the xml document about your mapping doesn't seem very dynamic to me.

Ayende Rahien commented on NHibernate Mapping -

Sat, 11 Apr 2009 10:45:07 GMT

Tobin, Yes, that is what it is for. It is useful in any case where you need to dynamically extend your entities.

Tobin Harris commented on NHibernate Mapping -

Sat, 11 Apr 2009 10:39:08 GMT

That's a great feature, I didn't even know it was there. So I guess this lets you do: var person = _session.Load