Thanks to all for you help and time. After reading to replies, I think that perhaps a clean way of dealing with individual and company customers in a single table could be to leave them out of the "parties" tree altogether and relate them to the "parties" table without a generalization hierarchy, but one-to- one from a "customers" table. For instance:
1) PARTIES TREE: Parent: PARTIES Attr: id, type Subtypes of Parties (complete and disjoint): INDIVIDUALS Attr: id, firstname, lastname, sex, language JURENTITIES Attr: id, name, type Subtypes of Individuals (complete and overlapping): PERSONAL Attr: id, birthday BUSINESS Attr: id, title, specialization 2) CUSTOMERS TREE: Parent: CUSTOMERS Attr: partyid (references parties), taxid, billingaddress Subtypes of customers (complete and overlapping): SUBSCRIBERS Attr: partyid (references parties), startdate, enddate SERVICE1USERS Attr: partyid (references parties), xxx SERVICE2USERS Attr: partyid (references parties), xxx 3) OUTSIDE BOTH TREES: PHONES Attr: id, number, areacode (relates M-M with parties) ADDRESSES Attr: id, street,etc (relates M-M with parties) EMAILS Attr: id, email (relates M-M with parties) URLS Attr: id, url (relates M-M with parties) The three would need an associative table separating them from the parties table, with a composite key Am I going wrong somewhere? Alberto -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
