in:
[select sum(tax_rate) as tax_rate from (tax_rates tr left join zones_to_geo_zones za on (tr.tax_zone_id = za.geo_zone_id) left join geo_zones tz on (tz.geo_zone_id = tr.tax_zone_id) ) where (za.zone_country_id is null or za.zone_country_id = 0 or za.zone_country_id = '223') and (za.zone_id is null or za.zone_id = 0 or za.zone_id = '43') and tr.tax_class_id = '0' group by tr.tax_priority]