On Wed, Feb 07, 2001 at 09:58:17AM -0500, Jim Lynch wrote:
> I've tried everything except standing on my head to get it to work.
> This example should show what I'm attempting to do. As long as the
> clause has only one element, it works.
>
> my $in_clause1="('abcdef','xzyrst')";
> my $in_clause2="('abcdef')";
>
> sth=$db->prepare("select * from table_x where txt in ?");
> $sth->execute($in_clause1);
> # that works
> $sth->execute($in_clause);
> # this doesn't
> I've tried also tried
>
> my $in_clause1="'abcdef','xzyrst'";
> my $in_clause2="'abcdef'";
>
> sth=$db->prepare("select * from table_x where txt in (?)");
>
> and gotten the same results. Can someone please tell me if it's
> possible to generate an IN clause on the fly and how?
This is a rather frequently asked question. You cannot use a placeholder
in the place of multiple values. Each placeholder substitutes for exactly
one value.
When I need to use placeholders for an arbitrary number of values, I
generally do something like this:
my @sth;
my @values = ('abcdef', 'ghijkl');
my $placeholders = join ', ', ('?') x @values;
$sth[@values] ||= $dbh->prepare(<<"EndOfSQL");
SELECT *
FROM my_table
WHERE my_column IN ($placeholders)
EndOfSQL
$sth[@values]->execute(@values);
That gives me one prepared statement handle for each count of values that
occurs.
Ronald
