- 

$DBversion = 'XXX';

if( CheckVersion( $DBversion ) ) {

    $dbh->do(q{

        UPDATE circulation_rules

        SET

            rule_value = CASE

                WHEN rule_value='0' THEN 'not_allowed'

                WHEN rule_value='1' THEN 'from_home_library'

                WHEN rule_value='2' THEN 'from_any_library'

                WHEN rule_value='3' THEN 'from_local_hold_group'

            END

        WHERE rule_name='holdallowed' AND rule_value >= 0 AND rule_value <= 3;

    });

    NewVersion( $DBversion, 27069, "Change holdallowed values from numbers to strings");

}