Re: Suggesting a libpq addition - Mailing list pgsql-hackers

Dmitriy Igrishin wrote:
> IMO, it would be better to implement some utility functions to
> make it easy to construct arrays dynamically for PQexecParams
> and PQexecPrepared. This seems to me more universal solution
> and it is useful for both -- high level libpq-libraries authors and for
> those who like to use libpq directly.

Is there a TODO here?

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> 
> 2010/12/6 Andrew Chernow <ac@esilo.com>
> 
> >
> >
> >> That would be a *HUGE* piece of software compared the relatively small
> >> thing I am suggesting...
> >>
> >>
> > Sometimes complex and large solutions are required for the simplest of
> > ideas.  I believe this is one of those cases.  You can't solve the "printf
> > style PQexec" properly by merely implementing a sprintf wrapper.
> >
> >
> >  As for escaping (or not escaping) of string arguments, that can be seen
> >> as a bug or a feature.  I do not wan't automatic escaping of string
> >> arguments in all cases, e.g. I might to construct an SQL statement with
> >> dynamic parts "WHERE xy" or "AND a = b".
> >>
> >> hypothetical example:
> >>
> >> filter = "WHERE name like 'Balmer%'";
> >> if (sort == SORT_DESC)
> >>        sort = " ORDER BY name DESCENDING";
> >>
> >> PQvexec(conn, "SELECT name, nr, id FROM address %s%s", filter, sort);
> >>
> >> So what I am aiming at right now is a PQvexec() function that basically
> >> has printf() like semantics, but adds an additional token to the format
> >> string (printf uses %s and %b to produce strings.) I am thinking of
> >> adding %S and %B, which produce strings that are escaped.
> >>
> >>
> > This suffers from becoming cryptic over time, see Tom Lane's comments back
> > in 2007 on this (
> > http://archives.postgresql.org/pgsql-hackers/2007-12/msg00362.php).
> > libpqtypes uses the human readable %schema.typename (schema is optional) to
> > specify format specifiers.  There is no learning curve or ambiguity, if you
> > want a point than use "%point", or "%my_type"....  libpqtypes allows you to
> > register aliases (PQregisterSubClasses) so that you can map %text to %s to
> > make it feel more like C..
> >
> >
> > --
> > Andrew Chernow
> > eSilo, LLC
> > every bit counts
> > http://www.esilo.com/
> >
> > --
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> > To make changes to your subscription:
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> >
> 
> 
> 
> -- 
> // Dmitriy.

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http://enterprisedb.com
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