Question

我的代码如下：

CREATE DATABASE IF NOT EXISTS store;

CREATE TABLE IF NOT EXISTS customer (

customer_id INT UNSIGNED NOT NULL AUTO_INCREMENT,

first_name VARCHAR(20) NOT NULL,

middle_name VARCHAR(20),

last_name VARCHAR(40) NOT NULL,

email VARCHAR(60) NOT NULL,

usr_pword CHAR(10) NOT NULL,

reg_date DATE,

PRIMARY KEY (customer_id),

FOREIGN KEY (rental_id) REFERENCES (rental_id),

UNIQUE (email)

);

CREATE TABLE IF NOT EXISTS rental (

rental_id INT UNSIGNED NOT NULL AUTO_INCREMENT,

date_out DATE NOT NULL,

date_in DATE NOT NULL,

cost INTEGER NOT NULL,

PRIMARY KEY (rental_id),

FOREIGN KEY (customer_id) REFERENCES (customer_id),

FOREIGN KEY (game_id) REFERENCES (game_id)

);

CREATE TABLE IF NOT EXISTS game (

game_id INT UNSIGNED NOT NULL  AUTO_INCREMENT,

game_name VARCHAR(60),

game_publisher VARCHAR(20),

PRIMARY KEY (game_id),

FOREIGN KEY (rental_id) REFERENCES (rental_id)

);

我得到错误：错误代码1064您的SQL语法错误...在'rental_id UNIQUE（email））附近;'

Answer 1

此行的语法无效，用于声明外键：

FOREIGN KEY (rental_id) REFERENCES (rental_id),

您必须在任何外键定义中声明引用的表。然后在表名后面，在括号中的表中声明引用的列。例如：

FOREIGN KEY (rental_id) REFERENCES `ReferencedTable` (rental_id),

您应该学习阅读SQL语法文档，因为它可以解决这个问题和其他问题。例如，http://dev.mysql.com/doc/refman/5.7/en/create-table.html显示外键引用的语法：

reference_definition:
    REFERENCES tbl_name (index_col_name,...)
      [MATCH FULL | MATCH PARTIAL | MATCH SIMPLE]
      [ON DELETE reference_option]
      [ON UPDATE reference_option]

请注意tbl_name如何跟随REFERENCES关键字，然后是括号列表。

检查语法参考文档应该是解决语法错误的第一种方法，就像你得到的那样。

MySQL Workbench 6.3中的奇怪语法错误

1 个答案: