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Specifying Primary Keys

If you are using a database that stores primary key information in its database server's schema information, the wizard skips this step. The wizard has already successfully read primary key information from the schema information and assigned primary keys to your model.

However, if primary key information isn't specified in your database server's schema information (as with Microsoft Access), the wizard now asks you to specify a primary key for each entity.

  1. Select movieId as the primary key for the Movie entity.

  2. Click Next.

  3. Select both movieId and talentId as the primary key for the MovieRole entity.

    MovieRole's primary key is compound; that is, it's composed of more than one attribute. Use a compound primary key when any single attribute isn't sufficient to uniquely identify a row. For MovieRole, the combination of the movieId and talentId attributes is guaranteed to uniquely identify a row.

  4. Click Next.

  5. Select talentId as the primary key for the Talent entity.

  6. Click Next.

© 1999 Apple Computer, Inc. – (Last Updated 24 Aug 99)