MySQL电影票预定销售系统局部ER图

### MySQL电影票预订销售系统的局部ER图设计

#### 实体关系概述
实体关系图（Entity Relationship Diagram, ERD）用于描述数据库中的表及其之间的关系。对于一个MySQL驱动的电影票预订销售系统而言，主要涉及几个核心实体：`Movie`, `Screening`, `Seat`, `Booking`, 和 `Customer`。

#### 主要实体定义

##### Movie (电影)
- **movie_id**: INT PRIMARY KEY AUTO_INCREMENT
- title: VARCHAR(255) NOT NULL
- release_date: DATE NOT NULL

##### Screening (放映场次)
- **screening_id**: INT PRIMARY KEY AUTO_INCREMENT
- movie_id: INT FOREIGN KEY REFERENCES Movie(movie_id), NOT NULL
- start_time: DATETIME NOT NULL
- end_time AS (start_time + INTERVAL duration_minutes MINUTE)

##### Seat (座位)
- **seat_id**: INT PRIMARY KEY AUTO_INCREMENT
- row_number: TINYINT UNSIGNED NOT NULL
- seat_number: TINYINT UNSIGNED NOT NULL
- theater_id: INT FOREIGN KEY REFERENCES Theater(theater_id), NOT NULL

##### Booking (预定记录)
- **booking_id**: INT PRIMARY KEY AUTO_INCREMENT
- customer_id: INT FOREIGN KEY REFERENCES Customer(customer_id), NOT NULL
- screening_id: INT FOREIGN KEY REFERENCES Screening(screening_id), NOT NULL
- booking_time: TIMESTAMP DEFAULT CURRENT_TIMESTAMP

##### Customer (顾客)
- first_name: VARCHAR(100) NOT NULL
- last_name: VARCHAR(100) NOT NULL
- email: VARCHAR(254) UNIQUE NOT NULL
- phone: CHAR(15)

CREATE TABLE IF NOT EXISTS Movie (
    movie_id INT AUTO_INCREMENT,
    title VARCHAR(255) NOT NULL,
    duration_minutes SMALLINT UNSIGNED NOT NULL,
    release_date DATE NOT NULL,
    PRIMARY KEY (movie_id)
);

CREATE TABLE IF NOT EXISTS Screening (
    screening_id INT AUTO_INCREMENT,
    movie_id INT NOT NULL,
    start_time DATETIME NOT NULL,
    end_time AS (start_time + INTERVAL duration_minutes MINUTE),
    PRIMARY KEY (screening_id),
    FOREIGN KEY (movie_id) REFERENCES Movie(movie_id)
);

CREATE TABLE IF NOT EXISTS Seat (
    seat_id INT AUTO_INCREMENT,
    row_number TINYINT UNSIGNED NOT NULL,
    seat_number TINYINT UNSIGNED NOT NULL,
    theater_id INT NOT NULL,
    PRIMARY KEY (seat_id),
    FOREIGN KEY (theater_id) REFERENCES Theater(theater_id)
);

CREATE TABLE IF NOT EXISTS Booking (
    booking_id INT AUTO_INCREMENT,
    customer_id INT NOT NULL,
    screening_id INT NOT NULL,
    booking_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (booking_id),
    FOREIGN KEY (customer_id) REFERENCES Customer(customer_id),
    FOREIGN KEY (screening_id) REFERENCES Screening(screening_id)
);

CREATE TABLE IF NOT EXISTS Customer (
    customer_id INT AUTO_INCREMENT,
    first_name VARCHAR(100) NOT NULL,
    last_name VARCHAR(100) NOT NULL,
    email VARCHAR(254) UNIQUE NOT NULL,
    phone CHAR(15),
    PRIMARY KEY (customer_id)
);

这些表格共同构成了一个简单的电影票预订销售系统的逻辑模型[^1]。此设计方案考虑到了实际应用场景下的基本需求，并确保了数据的一致性和完整性约束。