[DB-SIG] In praise of pyformat

[Paul Boddie]

On Sunday 12 August 2007 19:07, Mike Meyer wrote:
>
> How is "We only recognize parameter markers where we recognize
> parameter markers" *not* circular?

The SQL specifications dictate where parameter markers can be used. Please 
search for "SQL-92" and examine the specifications document for further 
details. It should be noted that what I have proposed previously is merely 
the introduction of the standard parameter marker as adopted by other major 
standards such as ODBC and JDBC.

[...]

> I think you just pinpointed the problem: parameter substitution in
> dbapi is being advertised as the solution to a problem it's not really
> adequate to solve. IIUC, it's restricted by the underlying SQL
> implementation (and inherits portability problems from there as
> well). That some underlying SQL implementations may not support it at
> all further complicates things.

PEP 249 (DB-API 2.0) refers to binding parameter values, not substituting 
values into the query, even if the latter does happen with some systems 
(after some modification of the values). So, no-one is really advertising 
parameters in the way you've described.

[...]

I agree that for some kinds of applications, there's a need for improved query 
building tools, especially for those of us who don't really see the 
attraction of object-relational mapping technology.

Meanwhile, we still need a better way of dealing with parameters. Having a 
database module tell me at runtime that its paramstyle is "xyz" is not 
particularly useful if I've already written my queries, and having lots of 
different modules with different paramstyles makes for a tedious exercise in 
providing queries for them all. And the pyformat style is just an anachronism 
providing a false convenience for the dubious benefit of module writers.

Paul