[DB-SIG] pyformat Parameter Style

[M.-A. Lemburg]

Marcos Sánchez Provencio wrote:
>>That said, I still think that positional binding is by far
>>the easiest to use and understand way of binding variables.
> 
> I see your point, but if you have to use your parameters several times
> in your sql statement it is a little awkward. For example, an optional
> filter parameter (imagine that with a combination of four or five
> parameters...):
> 
> select * from xx 
> where (yy=[param] or [param] is null) 
> and zz=[param2]

Uhm, why would you want to use "[param] is null" in SQL ? You
can check that in Python.

There are situations where you have to do multiple binding,
but that's not really harmful, e.g.

... where col1 > [param1] and col2 < [param1]

There's no additional overhead introduced by this,
since the two occurences of [param1] both refer to the same
Python object and the DB API modul can reuse the already
converted data a second time.

> I always thought this should be encapsulated in a stored procedure until
> I had to use Oracle. Oracle needs writing more than a dozen lines (not
> the intuitive kind, if I may say) to cram that into a stored proc.

Moreover, it's nowhere near as portable to use stored
procedures.

-- 
Marc-Andre Lemburg
eGenix.com

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