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Home -> Community -> Usenet -> comp.databases.theory -> Re: Is this bad design ?
> Suggestion A:
> Splitting the table in two were one table only holds the
> valid mothers and one table holds the non-valid mothers.
No. One table (Mothers) contains all mothers (valid and invalid) with all their attributes. The other table (ValidMothers) contains only the mother_ids of valid mothers. Thus ValidMothers models a *subset* of Mothers. Then, if you want a reference to only valid mothers, you can reference ValidMothers.mother_id instead of Mothers.mother_id.
Fabian Received on Thu Mar 11 2004 - 06:04:10 CST
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