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Re^3: Tree Structure and Dbby anonymized user 468275 (Curate) |
on Jul 07, 2005 at 11:18 UTC ( [id://473064]=note: print w/replies, xml ) | Need Help?? |
A link table is the normal way to enforce referential integrity in many to many relationships (0 or 1 counts as many for these purposes) and in this case prevents orphans; it also enables you to define different types of relationship without putting more illegal or awkwardly-implemented constraints (and adding maybe-null foreign keys for them) on the master table.
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