Assuming that you still agree with me that the object model and the data model are both derivable from the conceptual model, coding the DAL by hand makes little sense since the DAL would be derivable as well. Data driven mapping adds a dynamic layer on top of static structures, which seems wrong from the start. Plus it adds the burden of maintaining the mapping data as the conceptual model and it's derivatives change.

BTW, any attempt to derive the object model from the data model is doomed because a data model view of a conceptual model is analogous to a 2D view of 3D object. Some distortion is always introduced producing the 2D view and in the 2D view you never see the entire 3D object.

Having said this, there is no language that can formally and completely capture a conceptual model, not even ORM, so complete derivation is not possible and some hand coding inevitable. In my view the goal is to derive whatever is possible in such a way that as the conceptual model changes, the changes can be modeled and new derivation produced preserving as much of the hand coding that continues to be relevant as possible.

jMM

>I will have to think about that but I would be inclined to agree with you.
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>The question is: are you going to code that data access layer yourself, let the source be generated for you by a tool, or let a persistence layer figure it out by itself according to a mapping file that you give it.
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>>Hi neighbor, my mistake, I thought you meant ORM as in Object Role Modeling.
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>>From my perspective, an object model and a data model are both logical views of a conceptual model. If the data and object models can be derived from the conceptual model, then so can the data access layer that goes between them.
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>>jMM