No, the SF mapping is immutable On Fri, Sep 26, 2008 at 11:37 PM, Tuna Toksöz <[EMAIL PROTECTED]> wrote:
> 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 -~----------~----~----~----~------~----~------~--~---
