SQL 带外键的语法

Question

我有以下表格：

CREATE TABLE
IF NOT EXISTS {}.roles_permissions
(
role_id INT
(12) NOT NULL,
permission_id INT
(12) NOT NULL,
UNIQUE KEY
(role_id,permission_id)
CONSTRAINT `fk-rprole` FOREIGN KEY
(`role_id`)
REFERENCES `roles`
(`id`)
ON
DELETE CASCADE
ON
UPDATE CASCADE
CONSTRAINT (`fs_rppermission`) FOREIGN KEY
(`permission_id`)
REFERENCES `permissions`
(`id`)
ON
DELETE CASCADE
ON
UPDATE CASCADE
)

它报错了：- 你的 SQL 语法有误；查看与您的 MariaDB 服务器版本对应的手册，了解在 'CONSTRAINT fs_rppermission 附近使用的正确语法外键

有什么问题？

Answer 1

考虑：

CREATE TABLE IF NOT EXISTS roles_permissions (
    role_id INT(12) NOT NULL,
    permission_id INT(12) NOT NULL,
    UNIQUE KEY (role_id,permission_id),
    CONSTRAINT `fk-rprole` FOREIGN KEY (`role_id`) 
        REFERENCES `roles`(`id`)
        ON DELETE CASCADE ON UPDATE CASCADE,
    CONSTRAINT `fs_rppermission` FOREIGN KEY (`permission_id`)
        REFERENCES `permissions` (`id`)
        ON DELETE CASCADE ON UPDATE CASCADE
);

理由：

你的陈述中缺少逗号
外国名字不用括号
...适当的格式使语句更易于编写和阅读

Demo on DB Fiddle

SQL 带外键的语法

SQL syntax with FOREIGN KEY

sql

foreign-keys

create-table

mariadb