Entity-Relationship Model v.1

Diagram

Data requirements

Entities

Users

Represents the users of the system who can make room reservations or manage the system.

• Candidate keys: username, email
• Primary key: user_id

• Attributes:
  • user_id – integer, required
  • username – text, required, unique
  • email – text, required, unique
  • role – text, required (user/admin)

Rooms

Represents rooms that can be reserved in the system.

• Candidate keys: room_number
• Primary key: room_id

• Attributes:
  • room_id – integer, required
  • room_number – text, required, unique
  • capacity – integer, required
  • type – text, required (classroom, office, meeting room)

Reservations

Represents reservations made by users for specific rooms and time intervals.

• Candidate keys: (room_id, start_time, end_time)
• Primary key: reservation_id

• Attributes:
  • reservation_id – integer, required
  • start_time – datetime, required
  • end_time – datetime, required
  • user_id – integer, required
  • room_id – integer, required

Relationships

• Users – Reservations: One user can create multiple reservations, but each reservation is created by exactly one user.
• Rooms – Reservations: One room can be reserved multiple times, but each reservation refers to exactly one room.

Entity-Relationship Model History

• v1 – Initial ER model created according to the project requirements.