I am developing a travel management application. This design is as follows:
Each person on a journey is designated as a Traveler. Every traveler has a passport. Now the traveler can be MainMember or SubMember, depending on whether he is the head of the family. MainMember decides things like TourPackage, the total amount for his traveling family, etc. SubMemb depends on MainMember while traveling. So, if MainMember is deleted, all of its SubMembers should also be deleted.
So, the passenger has a passport. (One-to-One Relationships) The traveler is either MainMember or SubMember. (one to zero / one between Traveler-MainMember and Traveler-SubMember) MainMember can have several SubMembers. (one to many) SubMember has only one MainMembers. (Many to one)
My current ERD is something like the following.
As you can see, the three tables — Traveler, MainMember, and SubMember — formed a circular dependency. I am not sure if this will harm my application. If I delete the Traveler, which is MainMember, then 1. The entry from the Traveler is deleted. 2. The corresponding MainMember entry is deleted. 3. SubMember entries that are dependent on MainMember are deleted. 4. Traveler entries for SubMembers are deleted.
, Traveler-MainMember Traveler-SubMember (s). , .
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, @Daveo. , Traveler . SubMember .
ERD .
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, Hibernate? , Hibernate.
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