Re: bridge tables
Cascading referential integrity operations are for UPDATE and DELETE only. So if you change the primary key value or remove the rows in the author or book tables, dependent rows in tables that refer to those primary keys are also updated or deleted accordingly.
But there is no such thing as a cascading INSERT.
There's no way for referential integrity to infer that Herman Melville wrote Moby Dick just because you entered those two records in the authors and books tables respectively. It doesn't matter that you entered the records within a short period of time, or even within the same transaction. It still does not imply a relationship between that author and that book.
You need to enter a row with that information into the the bridge table explicitly.
Regards,
Bill K.
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November 15, 2006 10:36PM
Re: bridge tables
November 30, 2006 05:41PM
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