• Registered: 2020-03-31
  • Posts: 233

Topic: Primary and Foreign keys

Hi friends and Experts of MVD,
                                               Today I want to know about subject mentioned above in Topic subject. Can any one tell me how these keys act?
For example there is two table A and B. If A table has foreign key of B then what is action of table A and table .Same way if table B has foreign key of A then what will be act of B on A. Third condition is where both tables have foreign keys of each other then what will be the behaviour of the tables.

Thanks a lot.

  • k245
  • k245
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  • From: Deep
  • Registered: 2017-10-12
  • Posts: 1,545

Re: Primary and Foreign keys

In MVD for each table, a primary key is automatically created by the ID field, which is not displayed in the designer, but exists in the database.


A foreign key is automatically created when you add a field with the "LINK" type and support CASCADE or RESTRICT referential actions.


More detail:
https://en.wikipedia.org/wiki/Primary_key
https://en.wikipedia.org/wiki/Foreign_key

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