Hi Rajeev,
$baz is a variable that gets substituted for the ? in the prepare
statement, between the $dbh->prepare() and the $sth->execute.
So it's really:
$sth = $dbh->prepare("SELECT foo, bar FROM table WHERE baz=?");
... extra lines here... calculating $baz
$sth->execute( $baz );
Read a bit further down in perldoc DBI and you should hit a paragraph saying
The "?" characters are placeholders...
You don't have to use ? placeholders if you know well in advance what
you're looking for
and you don't want to run that same query multiple times with
different baz values.
$sth = $dbh->prepare("SELECT foo, bar FROM table WHERE baz=5");
$sth->execute();
is fine.
Hope this helps,
Stuart.
On Sat, Jul 30, 2011 at 8:13 AM, Rajeev Prasad <rp.ne...@yahoo.com> wrote:
> Hello,
>
> I am trying to understand this code from CPAN hepl page:
>
>
>
> $sth = $dbh->prepare("SELECT foo, bar FROM table WHERE baz=?");
> $sth->execute( $baz ); while ( @row = $sth->fetchrow_array ) { print
> "@row\n"; }
>
>
> what is execute doing here with $baz? what is $baz representing?
>
> thank you.
> Rajeev
>
