Tuesday, 7 November 2006

Tech Ed - ADO present and future

Jackie Goldstein. Renaissance Computer Systems
When coding optimistic concurrency handling with merge, get a refreshed datatable reflecting the new values in the database and fill a new datatable. Then using the original datatable.merge with the new datatable as the datatable parameter and true for the preserve changes parameter.

Sql dependancy for simple data result of a query has changed event handling in windows forms.

Handling database independence using the Syste.Data.Common db factory classes.

The next version of ado is the Entity Data Model. Its aims are to provide the client application a conceptual schema rather than the physical database schema. This client view is achieved by using the new client side map provider which is an extension of ado to provide the mapping at run time. The map provider returns datasets, datatables and atarows. Pros: each application can have its own specific view on the data. Cons: modelling is brought up to the client so while in code the objects are coded against, the developer still needs to know about the mapping.

To take the map provider further to an object model is object services which sits on top of the map provider to generate the object classes to return.

Hopefully the map provider and object services will be usable within a dll to provide a common dll om for clients to use.

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