问题描述
我有下表：
var myMap = new Map()
myMap.set('0','foo')
myMap.set('1','bar')
myMap.set('2','baz')
let iterator = myMap.keys();
let mapLastValue
for (i = 0; i < myMap.size; i += 1) {
mapLastValue = iterator.next().value
}
console.log(mapLastValue) // 2并显示错误：-您的sql语法有错误；请查看与您的MariaDB服务器版本相对应的手册，以在'CONSTRAINT 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
)
附近使用正确的语法
外键
出什么问题了？
解决方法
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
);
理论上：
-
在您的陈述中缺少逗号
-
外国人的名字不应该用括号括起来
-
...正确的格式使该语句更易于编写和阅读