When I have designed databases before, I have used a field within the parent / child tables for the relation. Speaking to someone recently it has been suggested that a cleaner / better way of achieving the same goal is to use link tables.
e.g.
My method
=========
Purchase order parent table
Order number (Used to link to the child table)
Supplier name
Delivery date
etc.
Purchase order child table
Order number (Used to link to the parent table)
Item number
item description
etc.
Alternative method
==================
Purchase order parent table
Order number (Used to link to the link table)
Supplier name
Delivery date
etc.
Link table
Order number (Used to link to the parent table)
Item number (Used to link to thechild table)
Purchase order child table
Item number (Used to link to the link table)
item description
etc.
The reason given that makes the alternative method better is that records can be entered into either table independently.
I can only see this being an advantage if the integrity of the database is lost.
Should I continue with the method I have used previously, or should I get my head round this alternative method?
Are there any another gains to the alternative method?
Thanks in advance for any thoughts on this matter.