to expand on what fabio is stating... what you want isn't possible. inheritance mapping works on type. once "set" it doesn't change. the classic example of animal, cat and dog. cat is an animal dog is an animal dog is not a cat (& vice verse)
once you have a dog you cannot change it to a cat. if you have an object that can be A, B, or C depending on the context of the work flow, then you will need to manage that in code. On Oct 22, 11:40 am, Fabio Maulo <[email protected]> wrote: > A row in the DB is the representation of the state of one object: which one? > > -- > Fabio Maulo > > El 22/10/2010, a las 12:05, Brian Chavez <[email protected]> escribió: > > Hi Fabio, > > Row 5 can be A, B, and C, depending on which one I'm requesting. > > The class hierarchy at A implements Id. > > class A{ > int Id{get;set;} > AProperty{get;set;} //Mapped to ColumnA in Table 1 > > } > > class B : A { > BProperty{get;set;} //Mapped to ColumnB in Table 1 > > } > > class C : B { > CProperty{get;set;} //Mapped to ColumnC in Table 1 > > } > > B and C only map extra properties which are column projections. > > CreateCriteria(typeof(A)).Add(Expression.Eq("Id", > 5)).UniqueResult<A>() > CreateCriteria(typeof(C)).Add(Expression.Eq("Id", > 5)).UniqueResult<C>() > > The Database Identity of A and C are the same. > The only difference is that C includes C.AProperty, C.BProperty, and > C.CProperty projection. Where as A only has A.AProeprty projection. > > Thanks, > Brian > > On Oct 22, 7:54 am, Fabio Maulo <[email protected]> wrote: > > A row in the DB is the representation of the state of one object: which one? > > -- > > Fabio Maulo > > El 22/10/2010, a las 11:40, Brian Chavez <[email protected]> escribió: > > Hi Alan, > > Thanks so much for the reply. I'm trying to avoid NHibernate using the > > database to determine the type of object. > > A single row in Table 1 can be projected into any object in the class > > hierarchy. > > For example, Row 5 is A, B, or C; depending on which type I'm > > requesting. > > If I CreateCriteria(typeof(C)), then NHibernate has enough information > > to know what type I'm requesting. > > I don't want NHibernate to extract type information from the database > > (ie: discriminator) because class A, B, and C can all represent any > > row in Table 1. > > The only difference between A, B, and C classes is the projections of > > the columns in the table. > > I hope that clarifies my situation. > > Any feedback would be appreciated! > > -Brian > > On Oct 22, 7:13 am, "[email protected]" > > <[email protected]> wrote: > > You can use formulas as discriminators as opposed to a column. You > > obviously have some sort of logic that determines the object type? > > On Oct 22, 9:02 am, Brian Chavez <[email protected]> wrote: > > Hello. > > Problem: > > I have 1 very large table of columns. > > I have a class hierarchy that represents different projections of the > > columns of this table. > > For example: > > class A{ > > AProperty{get;set;} //Mapped to ColumnA in Table 1 > > } > > class B : A { > > BProperty{get;set;} //Mapped to ColumnB in Table 1 > > } > > class C : B { > > CProperty{get;set;} > > } > > When I ask NHibernate to pull C, I expect to see C.AProperty, > > C.BProperty, and C.CProperty. > > Essentially, this class hierarchy represents different scoped > > projected views of the *same* table. > > How do I do this in hbm.xml mapping files without adding discriminator > > values? > > I've tried to use multiple <union-subclass> attributes and map to the > > same table, but NH throws an exception: > > --> NHibernate.DuplicateMappingException : Duplicate table mapping > > Table 1 > > Any ideas? > > Thanks, > > Brian > > -- > > 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 athttp:// > groups.google.com/group/nhusers?hl=en. > > -- > 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 > athttp://groups.google.com/group/nhusers?hl=en. -- 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.
