On Fri, May 17, 2013 at 5:22 PM, Michael Bayer <mike...@zzzcomputing.com> wrote: > > The major issue with format/pyformat is that too many DBAPIs take the easy > way out and just run their string through Python's "%" operator. This > causes DBAPIs that use the format styles to behave differently from those > that don't. In particular, a problem I have with MySQL-python and *maybe* > recent versions of psycopg2 (would have to check again) is that the behavior > changes whether or not I pass parameters to cursor.execute(). The same > statement that includes a "%" sign as part of the string must be passed > without escaping when no list/dictionary is passed as the second argument, > but when a list/dictionary is passed, the parsing changes and now the % sign > has to be escaped normally. This is an undocumented behavior that's > directly a side effect of the DBAPI saying, "oh there's parameters, let's > call "stmt % params", vs. not.
On this specific point you are right, and just yesterday I had to apologise for the inconsistency with a colleague of mine. This is something I would probably fix in an eventual "psycopg3" that would break compatibility with the past, but note that it would only affect functions that use the % operator and have no parameter: a minimal number (can't remember on top of my head if the % is used for other syntactical elements in postgres: not that I recall). OTOH if you want consistent behaviour with the %s and %%s just pass an empty tuple to queries taking no argument. You are a framework, you can do that (I would do that in psycopg by specifying the empty tuple as default argument for execute's params, or or something semantically equivalent). -- Daniele _______________________________________________ DB-SIG maillist - DB-SIG@python.org http://mail.python.org/mailman/listinfo/db-sig
