Calculation based on three tables

[Warren Nicholson]

I have 3 tables `Manifest`,Exporter` & `Importer`.
SELECT
Manifest.`MAN-ID`
Manifest.`Exporter`,
Manifest.`Importer`,
Manifest.Billing, [NB. dropdown menu exporter & importer]
Manifest.`Collect Zone A`, [NB. this will be a radio button]
Manifest.`Deliver Zone A` [NB. this will be a radio button]
FROM
Manifest

SELECT
`Exporter`.`EXP-ID`
`Exporter`.`Co Name`,
`Exporter`.`Collect Zone A`,
`Exporter`.`Deliver Zone A`
FROM
`Exporter`

SELECT
`Importer`.`IMP-ID`
`Importer`.`Co Name`,
`Importer`.`Collect Zone A`,
`Importer`.`Deliver Zone A`
FROM
`Importer`

When I insert a record into `Manifest` at the billing column I will put in either exporter or importer. This column will decide who pays for the cargo. If importer is inserted the query will get importer's rate/Collect Zone A (depending which radio buttons selected) and be charged accordingly. Basically I see the billing column as the comparator between exporter & importer. N.B there are many exporters & importers & everyone have unique rates.

Hope I described this scenario correctly.

Thanks

Warren