Multiple inheritance strategy with same base class

[Martyanov_Denis]

Hello.

I have base class, described as 

[Entity, Table('schema.global_table')]
[Inheritance(TInheritanceStrategy.JoinedTables)]
TGlobal = class

I have one inherited class

[Entity, Table('schema.joined_table')]
TJoinedGlobal = class (TGlobal)

with own fields in this table.

And, in third, I have an entity, that all field same as TGlobal, in DB stores in as table 'schema.global_name', but have also ManyValue-data in 'schema.third_table'.

I try describe it as 

[Entity]
TThird = class (TGlobal)

, without [Table()] attribute - got an error. 

Describe as

[Table('schema.table_name')]

• got a error then try to Manager.Save(ThirdObj) - it try to insert twice a record in table.

I want to describe it with inheritance in same table (I have special field in TGlobal to DicriminatorColumn attribute), but I need Joined strategy to my TJoinedGlobal class.

Can you help me with this trouble?

[wlandgraf (Wagner Landgraf)]

Hi,

I didn't understand your message completely. Some parts I got, some parts are confusing. You must have a Table attribute defined for all classes in a joined tables inheritance, because each class will save its declared fields/properties in its own table. You must either have [Table] attribute defined, or [Automapping] attribute. 

[Martyanov_Denis]

Ok, I'll try to say more clear...

I have table Global. Mapping class - TGlobal.

[Entity, Table('global')]
[Inheritance(TInheritanceStrategy.JoinedTables)]
TGlobal = class

One entity have some additional data - TChildOne = class (TGlobal) 

[wlandgraf (Wagner Landgraf)]

Yes, TChildOne must have a mapped table, so Aurelius know in which table it must save specific properties of TChildOne class.

[Martyanov_Denis]

Sorry for break.

One entity have some additional data - TChildOne = class (TGlobal) 

[Entity, Table('second_table')]
TChildOne = class (TGlobal)
  FSomeField: double;
  ...
end

This class have some own fields, and inherits fields from TGlobal.
All ok, code work fine.

But now, there is another entity, TChildTwo. It have all same fields with TGlobal, all data stores in table [Global].
But in DB where is additional table [GlobalParam] with relation many-to-many, between table [Global] and table [Param].
This table [GlobalParam] must be apply only for TChildTwo.

I try to describe TChildTwo as

  [Entity]
  [Table('GLOBAL')]
  TChildTwo = class(TGlobal)
  private
    [ManyValuedAssociation([TAssociationProp.Lazy, TAssociationProp.Required], [TCascadeType.SaveUpdate, TCascadeType.Merge], 'FParam')]
    FParams: Proxy>;
  ...

but when I try to execute DBManager.Save(ChildTwoObj), I got error - Aurelius try to insert second row in table [Global].
In table [Global] there are special field, which describe, what type of entity in record, so I can describe TChildTwo in Single table strategy with DescriminatorValue attribute, but TChildOne store data in separate table, and I need to use Joined Table Strategy for this class.

Is any opportunity to use two inheritence strategies, or I need to describe two base classes with different strategies?

[wlandgraf (Wagner Landgraf)]

You can't save TChildTwo in same table as global, because you are using joined inheritance and each class must save the fields in a different table, that's the concept of joined-tables inheritance. You must save it in a different table.