Hi All,
In developing PDBC (the web.database module) I decided there were 5 levels of database abstraction so perhaps we can agree on naming them like this:
Driver DB-API User Level API Portability Layer Object Relational Mapper
The driver is whatever libraries are used to connect to the database at the lowest level. The DB-API 2.0 wraps the driver functionality to allow low level database access for full control via SQL (perhaps with some sensible type conversions). The user level API wraps up the DB-API functionality into an easier to use form but doesn't abstract the database functionality, only the API. The portability layer provides database abstraction in both SQL and type conversions so that code works identically on all supported databases. The object relational mapper maps Python objects to SQL relationships so that no SQL is necessarily needed.
To the best of my knowledge PDO, PyDAL, adodb are what I would describe as user level APIs that is they simply wrap the DB-API methods in a more convenient and standard form. SQLObject is an Object Relational Mapper. The only portability layer I know of is my own. That is, an API that behaves EXACTLY the same with EXACTLY the same SQL commands on all supported databases by making a compromise between features and portability (regardless of whether we agree this is actually the best approach!)
It sounds like what is needed then is a DB-API with slightly less flexibility left to the implementor which takes into account any changes like the adoption of the datetime module and perhaps support for a reduced number of parameter types, tighter use of connection parameters etc. Are we also agreeing we need a user level API, perhaps similar to PDO to be included as part of the standard library?? If so, would we also include the database drivers themselves to provide database functionality out of the box? Is there no general desire to work on a portability layer or object relational mapper to be included in the standard library?
Cheers,
James _______________________________________________ DB-SIG maillist - DB-SIG@python.org http://mail.python.org/mailman/listinfo/db-sig
