ERModel v01

Diagram

Entities

User

This is the core entity that represents every person registered on PetSitter. It acts as a supertype for Admin/PetOwner/PetSitter so we can store the common attributes only in User.

Candidate keys:

• user_id - Primary key; numeric id, most efficient for indexing
• username - unique but not as efficient as user_id
• email - unique but not as efficient as user_id

Attributes:

• user_id - Numeric (Required, Unique, Auto-generated integer).

• username - Text (Required, Unique, 4-20 characters).

• first_name - Text (Required).

• last_name - Text (Required).

• password - Text (Required, Hashed format, Min. 8 characters).

• email - Text (Required, Unique, Standard email format).

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Admin

Subtype/specialization of User entity. Inherits from User. Has administrator privileges.

Candidate keys:

• user_id - Inherits user_id from User

Attributes:

• Inherits all attributes from User

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