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ERD: Many-to-Many or Parent-Child-Grandchild?

Question asked by Guy_Smith on Mar 8, 2013
Latest reply on Mar 16, 2013 by RayCologon

Thanks to the efforts of LaRetta and Michael, I now understand Join Tables a bit better and thought I solved a Many-to-Many Relationship with one, but now I'm even more 'confusedered' than when I started: I have people (Scouts) attending Events (Campouts, etc.) that are assigned to small groups of 8-10 (Patrols). Each patrol is then charged for costs they incur, which is different for each patrol and each event.


I originally though " OK, I have many people attending many events and many events can have many people attending them: An obvious many-to-many relationship, so I created three TO's: One for People, One for Events, and the Join Table (Patrols)". This setup works super for picking people to attend events, but that's about it.


Then I realized that my Join Table is wonky in that one direction is just fine: Events to Patrols is a One to Many: Each Event can have Many Patrols but each patrol can only belong to each event. The Problem is on the other side: Each Patrol can have many Scouts, but each scout can only be assigned to one patrol.


So...Do I actually have a many-to-many with People (?) or Patrols (?) as the Join Table or do I have a Parent-Child-Grandchild with Events having many patrols which in turn have many people?


Thanks much in advance for any help!