We'd like to reference foreign datasets by IDs only, so that we would be able to connect different records only using id, not a, maybe partial, selected entity.
For example:
[Entity]
TEntity = class
private
FId: TGUID;
...
public
property ID: TGUID read FId write FId;
end;
[Entity]
TAnotherEntity = class
private
FId: TGUID;
FEntityID: TGUID;
[Association([], CascadeTypeAll, 'FEntityID')]
FEntity: TEntity;
...
public
property ID: TGUID read FId write FId;
property EntityId: TGUID read FEntityId write FEntityId;
property Entity: TEntity read FEntity write FEntity;
end;
'FEntityID' as a new optional parameter for Association Attribute, would tell the Assocation, that there is already a field and this will not be created in Database, like MappedBy already does for ManyValuedAssociations.
So you could link TEntity and TAnotherEntity by setting Entity or EntityId.
In SQL both would do the same, setting ID-Field behind.
I think using composite ids this would not work, but for relations with only a single id-field this would be a great benefit.