How to do an exclusive specialization in sql?

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Well, I finished the entity relationship diagram of the database I’m creating and in it there is a service entity, which has two exclusionary specializations (one or the other, can’t be both), monthly and simple.

In the implementation generated 3 tables, monthly and simple has as a foreign key the service identifier, however, how can I prevent it is possible to implement the same instance in these two tables and to enforce this exclusive?

  • If I understood your problem solving a similar case by a triggercde statement, Tigger validated accregra.

  • If Mysql can use Schedule, in Oracle it is (Jobs or Scheduler), you will have to implement the restrictions in these triggers available in each DBMS.

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