3 tables: a, b, and c
When these 3 tables are joined, there is a combination of 3 fields, one field from each table, that should be unique.
Should there be a trigger that checks this condition on inserts/updates on each of these tables?
Randall
Bruno Wolff III wrote:
On Tue, Jan 06, 2004 at 07:10:28 +0000, Randall Smith <[EMAIL PROTECTED]> wrote:
Is it possible to create a unique constraint on multiple fields in related tables?
Not with the normal UNIQUE constraint. That will do multiple columns in one table, but won't span tables.
You can probably do what you want using triggers.
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