[Dbix-class] Escaping placeholders

[Tim Bunce]

On Sat, Dec 20, 2014 at 02:23:43PM -0800, Jonathan Leffler wrote:
> 
>      INSERT INTO SomeTable(DateTimeCol)
>                  VALUES(DATETIME[1](2014-12-31 23\:59\:59) YEAR TO SECOND);
> 
>    I really won't want people have to futz with their legitimate Informix SQL in order to pass it through
>    DBD::Informix.
>
>    Whatever is provided, whether by DBI or DBD::Informix, must accept the code without the
>    backslashes in front of the colons.  It is simply not acceptable to have to modify valid SQL to get it
>    past the gatekeeper code.

Understood. I wouldn't expect DBD::Informix to enable this by default.

We were only discussing a hypothetical situation where DBD::Informix
could optionally enable use of colon placeholders, if desired.

>    At the moment, the unescaped code works fine.  It will continue to work fine.  As long as DBI does not
>    break the currently working code, I will survive â€" like I have for the last decade and more.  Just
>    make sure that whatever you do does not break working valid Informix SQL code.

I have absolutely no intention of breaking anything :)

It'll be up to the individual driver authors to add support for escaping
placeholders, if they want to.

(The DBI has a built-in preparse function that's intended for parsing
placeholders but few, if any, drivers use it. I know DBD::Informix doesn't.)

Tim.

>    On Sat, Dec 20, 2014 at 2:17 PM, Tim Bunce <[2]Tim.Bunce at pobox.com> wrote:
> 
>      On Sat, Dec 20, 2014 at 01:14:29PM -0800, Jonathan Leffler wrote:
>      >    Many, many years ago, DBD::Informix had to give up on the DBI-provided parsing for placeholders
>      because
>      >    there were too many contexts in which it was wrong for Informix.  It may have improved since
>      then, but:
>      >
>      >          INSERT INTO SomeTable(DateTimeCol)
>      >            VALUES(DATETIME(2014-12-31 23:59:59) YEAR TO SECOND);
> 
>      >    I think I raised this as an issue back in the 1996-1998 timeframe (I said 'many years ago' and
>      meant
>      >    it).  I'd have to dig through my release notes to be more precise.  Informix only supports
>      natively the
>      >    `?` placeholders.  It doesn't yet have the complexities introduced by the PostgreSQL operators.
>      >
>      >    I don't know whether this can be handled at all.  It may be that DBD::Informix has to stay out in
>      >    isolation but it would be nice if it wasn't necessary.
> 
>      The `?` placeholders are 'standard' (for some definition) so DBD::Informix
>      isn't really 'in isolation'. There are quite a few drivers that only
>      support `?` placeholders.
> 
>      In theory, if this proposal goes ahead, and is applied to `:` placeholders
>      as seems likely, then you'd be able to write the above as:
>                  INSERT INTO SomeTable(DateTimeCol)
>                    VALUES(DATETIME[3](2014-12-31 23\:59\:59) YEAR TO SECOND);
> 
>      Tim.
> 
>    --
>    Jonathan Leffler <[4]jonathan.leffler at gmail.com>  #include <disclaimer.h>
>    Guardian of DBD::Informix - v2013.0521 - [5]http://dbi.perl.org
>    "Blessed are we who can laugh at ourselves, for we shall never cease to be amused."
> 
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