So my question is can we add new mappings for classes after the session factory is initialized?If yes, you are very correct, if not, you can always change mapping.
On Fri, Sep 26, 2008 at 11:35 PM, Peter Lin <[EMAIL PROTECTED]> wrote: > > > for those who haven't read the latest edition of hibernate book by > gavin. from chapter 13 page 584, he provides an example of a query > generated by hibernate for classes that use discriminator > > > select > b1.BILLING_DETAILS_ID, > b1.OWNER, > b1.USER_ID, > b2.ACCOUNT, > b2.BANKNAME, > b2.SWIFT, > b1.BILLING_DETAILS_TYPE as clazz > from > BILLING_DETAILS b1 > > In gavin's example, BILLINGS_DETAILS_TYPE is the discriminator > column. In order for polymorphic queries to work properly in > Hibernate and NHibernate, it looks at billings details type and then > determines which class to instantiate. Even though my use case doesn't > have a subclass at the present, there will be subclasses eventually. > Logically, the select statement for all discriminated classes need to > include the discriminator column. Other clearly disagree, or have a > different understanding of how polymorphic queries should work. Having > worked on and used other ORM tools, the approach used by other tools > is to always include the discriminator column. > > peter > > > > > On Sep 26, 3:38 pm, "Ayende Rahien" <[EMAIL PROTECTED]> wrote: > > Using a where="" is the appropriate action here, not a discriminator. > > > > On Fri, Sep 26, 2008 at 10:36 PM, Peter Lin <[EMAIL PROTECTED]> wrote: > > > > > sorry for the confusing explanations. I'll attempt to explain it > > > better. > > > > > Here is the situation. > > > > > I. I have a table in a legacy database which has existing records > > > which use the concept of a discriminator. In other words, there is a > > > type_code column, which has different values. > > > > > II. I have a C# object which represents an entity. The entity maps to > > > records in the table with a specific discriminator value. > > > > > III. I only want to get the records with a specific discriminator > > > value from the table like "home_address". > > > > > IV. I have a modeling tool which generates C# classes with the > > > appropriate NH attributes. Changing the code gen for the special case > > > to use one of the work arounds feels like a hack to me. > > > > > V. since polymorphic queries require the discriminator column to > > > create the correct object instance, shouldn't it always include it in > > > the select part of the sql statement? > > > > > thanks for taking time to listen and respond. > > > > > peter > > > > > On Sep 26, 3:20 pm, "Jon Palmer" <[EMAIL PROTECTED]> wrote: > > > > If you have only one class mapped then the only thing it can return > is > > > > that one class so why would it need the address_type_code column? > > > > > > One of your previous emails indicated the problem was returning all > rows > > > > from the table. I'm confused about what the problem is your tryign to > > > > solve. > > > > > > Jon > > > -- Tuna Toksöz Typos included to enhance the readers attention! --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "nhusers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/nhusers?hl=en -~----------~----~----~----~------~----~------~--~---
