Here are my requirements:

  • one user can have many tasks
  • one group can have many task
  • one group can have many users
  • only invited user by a user can be added into a group

Does this db design appear to model these requirements?

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In group table, group_id should be the FK of which? there are 2 table linked to that table. 1 FK to 2 PK? possible?

1 Answer 1


Try these design which will satisfy your requirements.


 - Group Id Primary Key
 - Group Name)


- User Id Primary Key
- Name
- Email 
- Created on 
- Group Id references Group(Group Id), Referred User ID references User(User ID))


- Task ID Primary Key 
- Name 
- Priority 
- Date)


- Relation ID Primary Key 
- User ID references User(User ID)
- Task ID references Task(Task ID))
  • relation id PK in user-tasks table is for? not compulsory right? Dec 6, 2013 at 7:34

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