[DB-SIG] Database Independent SQL
Sun, 8 Sep 2002 19:02:00 -0700
On Sunday, Sep 8, 2002, at 18:44 US/Pacific, Huy Do wrote:
> I'm about to develop a major Python application and was wondering what
> most database independent way of going about accessing a database in my
> application. i.e so I can switch between databases almost instantly (a
> little bit of work is also okay :-)).
Depending on 'how portable' you wanted to be, and how complicated the
For example, if you were restricting yourself to just MySQL and
PostgreSQL, you could almost get away with simply doing a 'drop in
replacement' between the two (as long as you didnt use foreign keys, or
auto increment, or any of the other PG/My dependant things).
However, if you think you want a bit more portability, or even want to
use some of the advanced features of just one or two database, the BEST
way is to contain all your database-access code into a single module
(or a grouping). This way, if you need to change, all your database
stuff is isolated.
def __init__ ( self ):
self.db = PyPgSQL.connect ( lotsofparams)
def add_thingy ( self, thingy ):
cur = self.db.cursor ()
cur.execute ( "insert into thingy ( id, name, properties )
values ( %(id)s, %(name)s, %(props) )", vars(thingy)
... and so on.
You can then perhaps create a switch in the __init__ function that
connects to a different database, and other functions that use
database-dependant stuff would change appropriately. the DB-API gives
you portable /access/, but not portable /use/.
The rest of your code uses your application-specific DB layer, so won't
care if you change the backend implementation.
("`-/")_.-'"``-._ Ch'marr, a.k.a.
. . `; -._ )-;-,_`) Chris Cogdon <email@example.com>
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