Best design for parent-child related data - please help !
I'm designing a database for customer management. Usually our customers have a headquarter and several subsidiary. I've designed in the database one table to hold all the data for customers with an extra column for specifing the parent (in case of a subisdiary):
ParentID (filled with CustomerID of the parent in case of subsidiary)
In the case of headquarter the ParentID field is not filled.
Is this a good design ? Should I better put them in two separate tables (one for headquarters and one for subsidiaries) and to have a traditional one-to-many realtionship between those two tables ?
Any advice, pros and cons would be highly appreciated.