dvds inherits all the fields from video, but, it also adds additional specific fields that are pertinent to dvd's
I could insert a star wars dvd into the dvd table. To populate all the fields, I would need to supply all the fields from video, AND the dvd-specific fields as well. I could insert a tape into the tapes table, only supplying the ID, title, and and duration fields.
Then, if I select from either table, I would only see the one entry per table. However, I could SELECT * from VIDEO, and see the common data for both movies.
Last edited by loquin; 07-31-06 at 13:53.
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