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学校の宿題で、私と友達が頭を悩ませています...だから、これは私が一度に1つずつ実行した私のクエリです...

CREATE DATABASE GamblingSociety;

USE GamblingSociety;

CREATE TABLE GamblingDen
(
    Name VARCHAR (20) PRIMARY KEY,
    Address VARCHAR (50),
    Phone VARCHAR (10)
);

CREATE TABLE Room (
    RoomNr INT,
    GameCapaity INT,
    GamblingDenName VARCHAR (20),
    PRIMARY KEY (RoomNr, GamblingDenName),
    FOREIGN KEY (GamblingDenName) REFERENCES GamblingDen (Name)
);

CREATE TABLE Employee (
    SSN CHAR (11) PRIMARY KEY,
    Name VARCHAR (20),
    Address VARCHAR(50),
    Salary INT,
    isBoss BOOL,
    GamblingDenName VARCHAR (20),
    FOREIGN KEY (GamblingDenName) REFERENCES GamblingDen (Name)
);

CREATE TABLE GameType (
    Name VARCHAR (20) PRIMARY KEY,
    WinningProcentage FLOAT,
    ResponsibleEmployee CHAR (11),
    FOREIGN KEY (ResponsibleEmployee) REFERENCES Employee (SSN)
);

CREATE TABLE Supplier (
    Name VARCHAR (20) PRIMARY KEY,
    Address VARCHAR (50)
);

CREATE TABLE SupplierOfGameType (
    SupplierName VARCHAR (20),
    GameTypeName VARCHAR (20),
    PRIMARY KEY(SupplierName, GameTypeName),
    FOREIGN KEY (SupplierName) REFERENCES Supplier (Name),
    FOREIGN KEY (GameTypeName) REFERENCES GameType (Name)
);

CREATE TABLE GamblingTable (
    TableNr INT,
    RoomNr INT,
    GamblingDenName VARCHAR (20),
    GameTypeName VARCHAR (20),
    Comments VARCHAR (128),
    PRIMARY KEY (RoomNr, TableNr, GamblingDenName, GameTypeName),
    FOREIGN KEY (RoomNr, GamblingDenName) REFERENCES Room (RoomNr, GamblingDenName),
    FOREIGN KEY (GameTypeName) REFERENCES GameType (Name)
);

CREATE TABLE Shylock (
    Phone CHAR (10) PRIMARY KEY,
    Name VARCHAR (20),
    Contry CHAR (3)
);

CREATE TABLE Customer (
    SSN CHAR (11) PRIMARY KEY,
    Name VARCHAR (20),
    Phone CHAR (10),
    Address VARCHAR (50)
);

しかし、この最後のクエリは機能しません:

USE GamblingSociety;

CREATE TABLE GamblingInstance (
    StartTime DATETIME,
    EndingTime DATETIME,
    GamblingDenName VARCHAR (20),
    TableNr INT, 
    GameTypeName VARCHAR (20), 
    Customer CHAR (11),
    Shylock CHAR (10), 
    Debt INT, 
    DebtPayed BOOL,
    DebtPayedDate DATETIME,
    PRIMARY KEY (StartTime, GameTypeName, Customer),
    FOREIGN KEY (GamblingDenName, TableNr, GameTypeName) REFERENCES GamblingTable (GamblingDenName, TableNr, GameTypeName),
    FOREIGN KEY (Customer) REFERENCES Customer (SSN),
    FOREIGN KEY (Shylock) REFERENCES Shylock (Phone)
);

「エラー コード: 1005。テーブル 'gamblingsociety.gamblinginstance' を作成できません (errno: 150)」というエラーが表示されます。

これを置き換えると：

FOREIGN KEY (GamblingDenName, TableNr, GameTypeName) REFERENCES GamblingTable (GamblingDenName, TableNr, GameTypeName),

これとともに：

FOREIGN KEY (GameTypeName) REFERENCES GamblingTable (GameTypeName),

それは機能するので、GamblingDenName と TableNr の何かです。

そして、私はそれをグーグルで検索し、多くのヒントを見つけましたが、何もうまくいきませんでした...

それで、何か考えがある人はいますか？

前もって感謝します！

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1 に答える 1

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GamblingTableこのREFERENCEを満たすことができるキーはありません:

  REFERENCES GamblingTable (GamblingDenName, TableNr, GameTypeName),

つまり、唯一の列、または最初の 3 つの列でGamblingTableあるキーはありません。GamblingDenName, TableNr, GameTypeName

を満たすキーがあり、REFERENCES GamblingTable (GameTypeName)それがそのバージョンが機能する理由です。

(FOREIGN KEY が他の FOREIGN KEY の親として使用されているのを実際に見たことはないと言わざるを得ませんが、うまくいくと思います)。

于 2011-09-27T22:10:02.880 に答える