Нормализација

Почетна релација:

R(UserId, FirstName, LastName, Email, Username, Password, City, Neighborhood, Bio, Quote, BookId, Title, Author, Language, !ImageURL, !BookISBNId, ISBN, GenreId, Genre, InventoryId, Availability, Condition, WishId, Priority, RequestId, RequestStatus, RequestDate, TransactionId, BorrowDate, ReturnDate, BorrowDuration, SwapId, ReviewId, Rating, ReviewerComment, ReviewDate, MessageId, MsgTime, MsgDate, MessageContent, FriendshipId, DateCreated, FriendshipStatus, ReportId, ReportType, ReportDate, Details, ReportStatus, ReportedEntity, NotificationId, Type, NotifTime, NotifDate, Description, NotificationStatus)

Функционални зависности:

UserId -> FirstName, LastName, Email, Username, Password, City, Neighborhood, Bio, Quote

Email -> UserId, FirstName, LastName, Username, Password, City, Neighborhood, Bio, Quote

Username -> UserId, FirstName, LastName, Email, Password, City, Neighborhood, Bio, Quote

BookId -> Title, Author, Language, !ImageURL

!BookISBNId -> BookId, ISBN

GenreId -> BookId, Genre

InventoryId-> UserId, Availability, Condition, BookId

WishId -> UserId, Priority, BookId

RequestId -> UserId, BookId, InventoryId, RequestStatus, RequestDate

TransactionId -> RequestId, UserId, InventoryId, BorrowDate, ReturnDate, BorrowDuration

SwapId -> TransactionId

ReviewId -> TransactionId, UserId, Rating, ReviewerComment, ReviewDate

MessageId -> UserId, MsgTime, MsgDate, MessageContent

FriendshipId -> UserId, DateCreated, FriendshipStatus

ReportId -> UserId, ReportType, ReportDate, Details, ReportStatus, ReportedEntity

Notification -> NotificationId, TransactionId, MessageId, FriendshipId, RequestId, Type, NotifTime, NotifDate, Description, NotificationStatus

---

Лево: BookISBNId, GenreId, WishId, SwapId, ReviewId, ReportId

Десно: FirstName, LastName, Password, City, Neighborhood, Bio, Quote, Title, Author, Language, !ImageURL, ISBN, Genre, Availability, Condition, Priority, RequestStatus, RequestDate, BorrowDate, ReturnDate, BorrowDuration, Rating, ReviewerComment, ReviewDate, MsgTime, MsgDate, MessageContent ,DateCreated, FriendshipStatus, ReportType, ReportDate, Details, ReportStatus, ReportedEntity, Type, NotifTime, NotifDate, Description, NotificationStatus

Од двете страни: UserId, Email, Username, BookId, InventoryId, RequestId, TransactionId, MessageId, FriendshipId, NotificationId

---

BookISBNId += {BookId, ISBN, Title, Author, Language, !ImageURL}

Не ги содржи сите атрибути

GenreId += {BookId, Genre, Title, Author, Language, !ImageURL}

Не ги содржи сите атрибути

WishId += {UserId, Priority, BookId, Title, Author, Language, !ImageURL, FirstName, LastName, Email, Username, Password, City, Neighborhood, Bio, Quote}

Не ги содржи сите атрибути

SwapId += {TransactionId, RequestId, UserId, InventoryId, BorrowDate, ReturnDate, BorrowDuration, BookId, RequestStatus, RequestDate, FirstName, LastName, Email, Username, Password, City, Neighborhood, Bio, Quote, Availability, Condition, Title, Author, Language, !ImageURL}

Не ги содржи сите атрибути

ReviewId += {TransactionId, UserId, Rating, ReviewerComment, ReviewDate, RequestId, InventoryId, BorrowDate, ReturnDate, BorrowDuration, FirstName, LastName, Email, Username, Password, City, Neighborhood, Bio, Quote, BookId, RequestStatus, RequestDate, Availability, Condition, Title, Author, Language, !ImageURL}

Не ги содржи сите атрибути

ReportId += {UserId, ReportType, ReportDate, Details, ReportStatus, ReportedEntity, FirstName, LastName, Email, Username, Password, City, Neighborhood, Bio, Quote}

Не ги содржи сите атрибути

ReviewId, BookISBNId, GenreId, WishId, SwapId, ReportId = { ReviewId, !BookISBNId, GenreId, WishId, SwapId, ReportId, NotificationId, TransactionId, UserId, Rating, ReviewerComment, ReviewDate, InventoryId, BorrowDate, ReturnDate, BorrowDuration, FirstName, LastName, Email, Username, Password, City, Neighborhood, Bio, Quote, Availability, Condition, BookId, Title, Author, Language, !ImageURL, ISBN, Genre, Priority, ReportType, ReportDate, Details, ReportStatus, ReportedEntity, MessageId, FriendshipId, RequestId, Type, NotifTime, NotifDate, Description, NotificationStatus, MsgTime, MsgDate, MessageContent, DateCreated, FriendshipStatus, RequestStatus, RequestDate} Следува дека е единствен кандидат клуч и го прогласуваме за примарен клуч.

Декомпозиција до највисока можна нормална форма

Релацијата R е во 1НФ, со тоа што вредностите на сите атрибути се атомични, но не е во 2НФ, бидејќи за релацијата не е точно дека секој не-примарен атрибут е целосно функционално зависен од примарниот клуч (ReviewId, BookISBNId, GenreId, WishId, SwapId, ReportId), и со тоа имаме парцијални зависности кои ја нарушуваат 2НФ.