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# $dbh contains your database handle
my $sth = $dbh->prepare( "SELECT * FROM foo WHERE id = ? AND bar = ?" 
+) or die( "Could not prepare statement: ".$dbh->errstr() ); #of cours
+e you will have a more elegant error handling method than just die
$sth->execute( $value_for_id, $value_for_bar );
#and then just fetch the data like you would normally.

#Take the same $sth from the previous example
my @data_to_query = ( #You would probably get this from somewhere else
...
    $sth->execute( $_->{id}, $_->{bar} );
    #do something with that dataset
}