On Fri, Aug 06, 2004 at 01:38:48PM +0100, Alan Burlison wrote:
> I want to use the DBD::mysql 'mysql_use_result' attribute to make the
> driver use mysql_use_result instead of mysql_store_result, and I want to
> do it for all the queries I'm submitting against the database. Having
> to set it on each and every statement handle that I generate is a real
> pain, I'd like to be able to set the default on the database handle and
> have it inherited by all the statement handles that are generated from
> the database handle.
>
> I'm not sure of the best way to go about this, there are two options:
>
> 1. Store the value in the DBH and copy into the STH when the STH is
> created, unless the STD constructor is given an explicit value.
>
> 2. Store the value in the DBH and each time the STH is executed, look up
> the value in the parent DBH if the STH doesn't have an explicit value.
>
> e.g. given:
>
> $dbh->{mysql_use_result} = 1;
> my $sth = $dbh->prepare(...);
> $dbh->{mysql_use_result} = 0;
>
> under option 1, when $sth is executed the value of the mysql_use_result
> attribute will be 1, and under option 2 it will be 0.
Use option 1.
So the code in dbd_st_prepare would look like:
imp_sth->use_mysql_use_result = svp ? SvTRUE(*svp) : imp_dbh->use_mysql_use_result
> One other question - how do I get the parent DBH from a STH from within
> the XS code for a DBD driver?
Anywhere there's an imp_sth in scope you can declare a imp_dbh this way:
D_imp_dbh_from_sth;
That's a macro that expands to D_imp_from_child(imp_dbh, imp_dbh_t, imp_sth).
[Which expands to imp_dbh_t *imp_dbh = (imp_dbh_t*)(DBIc_PARENT_COM(imp_sth))]
Tim
p.s. Questions like this would be better directed to dbi-dev.
