Hello, I encountered a problem when designing a database. There is a so-called cyclic connection.
For information: the subject area - GEF of the 3rd generation, the projected database should provide input and storage of the final grades of high school graduates by disciplines and display information on academic performance by competence. data schema The essence is as follows: There is a specialty (specialty) for which a set of disciplines is characteristic (descipline), they are connected by many to many attitudes and a set of competencies (competention), competences are characteristic of one specialty, i.e. One specialty includes several competencies. Further, the circus itself, the competences consist of several disciplines, and one discipline is included in several competencies within the competence of the dispipline has its weight field (weigth) in the table (competention_discipline). Also, within the framework of the specialty, each discipline has a certain total number of hours (I think this field (total_hours) in the table is discipline_speciality )

I ask for help in the following:

  1. Is this connection correct in this database (see figure)? (Explain your opinion)
  2. The field total number of hours per discipline must be kept in that table (see italics above)?
  • Are you kidding or what? Those guys are not visible even with a 1000% increase. - Sergey
  • @Sergey, source on google - Eugene Stepanov
  • Within the framework of the base, any links, including cyclic ones, are permissible, if necessary. And according to the description of the essence I did not see any cyclicity. Specialty -> Discipline, Specialty -> Competence, Competence -> Discipline. Three branches - three dead ends. But you are not going to walk in a circle Specialty -> Discipline -> Competence -> Discipline -> Specialty -> ...? - Sergey

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