如何传递外键以在 php 中创建表

Question

Here is my two tables, I want to pass my guest_id as a foreign key inside reservation table. but it's given error..

$sql = "CREATE TABLE MyGuests (
    guest_id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
    firstname VARCHAR(30) NOT NULL,
    lastname VARCHAR(30) NOT NULL,
    email VARCHAR(50),
    reg_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
    )";

// // sql to create table

$sql = "CREATE TABLE reservation (
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
FOREIGN KEY(guest_id) REFERENCES MyGuests(guest_id),
room INT(11) NOT NULL,
price FLOAT(11) NOT NULL,
reg_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
)";

where is the problem?

Answer 1

You need also add the column guest_id to your table reservation

Like:

$sql = "CREATE TABLE MyGuests (
    guest_id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
    firstname VARCHAR(30) NOT NULL,
    lastname VARCHAR(30) NOT NULL,
    email VARCHAR(50),
    reg_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
    )";

// // sql to create table

$sql = "CREATE TABLE reservation (
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
guest_id INT(6) UNSIGNED,
room INT(11) NOT NULL,
price FLOAT(11) NOT NULL,
reg_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
FOREIGN KEY(guest_id) REFERENCES MyGuests(guest_id)
)";