Consider the following scenario:

This year, 2019, the finals of the African Cup of Nations soccer tournament were hosted by Egypt. A number of countries were involved, in fact, 24 of them, even though this number can vary for each tournament. Each country had a number of players that participated. The African football (soccer) governing body, the Confederation of African Football (CAF) rules stipulate that a person can only play for one country. Each country had a number of specialists, such as managers, doctors, treasurer, ambulance drivers, etc to cater to its different needs. Even though most specialists were attached to one country, some of them such as ambulance drivers catered to more than one country.

I was given the following instruction:

Draw an entity-relationship diagram (ERD) for this scenario. Do not include entities that are not in the scope (scenario) provided above. The ERD should not contain any many-to-many relationships. No attributes/fields are required.

I started drawing the diagram so my attempted drawing of the erd

but I got stuck in the relationship between Country and Specialist. The instruction states that no many-to-many relationships should be presented in the diagram. The scenario indicates that one specialist can belong to more than one country. What should I now do? There's clearly a many-to-many relationship between Country and Specialist. Thank you.

  • 1
    You'll have to ask your professor about this discrepancy. Without many to many relationships or linking tables (apparently disallowed), there's no way out of the conundrum. – Robert Harvey Nov 20 at 21:17
  • Thank you. Let me ask you, what if I draw a second Country entity and make a one-to-many relationship to it (from Specialist)? That would be technically correct, right? – Clint Theron Nov 20 at 21:26
  • @RobertHarvey, I also want to ask, is my answer correct (if we take away the cardinality between Country and Specialist)? – Clint Theron Nov 20 at 21:32

School assignments are weird, so you should ask your professor. Depending on what has been covered so far, you might be expected to just recognize the many-to-many relationships and omit them, or you might be expected to create something like an intersection entity that has a one-to-many relationship with both specialists and countries. You could call it service agreement or something like that.

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  • Thank you. I think it's this one "you might be expected to just recognize the many-to-many relationships and omit them" because I looked at the marks awarded and it is 7. So 3 for the 3 entities and 4 for the cardinality. It makes sense that way. Thanks again :-) – Clint Theron Nov 20 at 22:25

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