however? i am confused. do you have to have related tables for an auto populate field when one field is selected from a drop down menu?
Not in every case, but the alternatives usually aren't good alternatives to use for this where the related table works very nicely in almost all cases.
If you have multiple contacts that are linked to the same company, then yes, you should have a table for contacts and a table for companies with a link between them such as:
Contacts::CompanyID = Companies::CompanyID
And companyID is not the name of the company, it's a serial number field defined in the companies table.
ok. thanks for the info. however wouldnt it be the way, or would this be incorrect?
Contacts::ContactsID = Companies::CompanyID
If many contacts can link to the same company, then you want to match by the company ID.
If you have five contacts associated with "Acme Systems Inc" and it's companyID number is 2345, then all Five contact records would store 2345 in their match fields. Since this is the ID of the company, not the individual contact recordss, the field is best named as CompanyID when you add this field to your contacts table. The ContactID field should be a field used to uniquely identify each contact and should also be a serial number field, but it would not be used for this specific relationship.