my $fromwhere = 'FROM rate_prefix'.
' WHERE rate_prefix.regionnum = rate_region.regionnum';
$select .= "( SELECT countrycode $fromwhere LIMIT 1 ) AS ccode,
- ARRAY_TO_STRING( ARRAY(SELECT npa $fromwhere), ',' ) AS prefixes";
+ ARRAY_TO_STRING( ARRAY(SELECT npa $fromwhere AND npa IS NOT NULL), ',' ) AS prefixes";
} elsif ( driver_name =~ /^mysql/i ) {
$join = 'LEFT JOIN rate_prefix USING ( regionnum )';
$select .= "GROUP_CONCAT( DISTINCT countrycode ) AS ccode,