Comp Sci How to Correctly Model Captains and Players in an NHL ER Diagram?

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The discussion centers on modeling an NHL database with specific requirements for teams, players, and games. It highlights the confusion around using "ISA" to differentiate between captains and players, suggesting that they should not be treated as separate entities. Participants emphasize that a captain is inherently a player, indicating a need for generalization rather than distinct entities. The conversation also touches on the importance of focusing on entity relationship diagrams rather than functional dependency diagrams in this context. Ultimately, the consensus is that the initial approach to modeling captains and players needs correction.
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Homework Statement
My main confusion is can I use "ISA" in captain and player? Can I use generalization there?
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Suppose you are given the following requirements for a simple database for the National Hockey League (NHL):
1) the NHL has many teams,

2) each team has a name, a city, a coach, a captain, and a set of players.

3) each player belongs to only one team,

4) each player has a name, a position (such as left wing or goalie), a skill level, and a set of injury records,

5) a team captain is also a player,

6) a game is played between two teams (referred to as host_team and guest_team) and has a date (such as May 11th, 1999) and a score (such as 4 to 2).
Here's my solution. Is it correct?
_x1alSrtX1a24LpxNl7LpFD-UbpUUr0TCYqfYOFCNXui8u53vA.png

My main confusion is can I use "ISA" in captain and player? Can I use generalization there?Here's the solution to this problem.
https://www2.cs.sfu.ca/CourseCentral/354/louie/Chap2_practice_key.pdf
 
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Don't you usually do a functional dependency diagram?
 
WWGD said:
Don't you usually do a functional dependency diagram?
Not when the question asks for an entity relationship diagram :-p (see the title)
shivajikobardan said:
Homework Statement:: My main confusion is can I use "ISA" in captain and player? Can I use generalization there?
No, your main confusion is that you have two different entities for "captain" and "player".
 
pbuk said:
No, your main confusion is that you have two different entities for "captain" and "player".
Hmm, so that's a mistake in your opinion?
 

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