引用时无法在mysql中创建表

数据库中确实存在带有键

aid

的ADDR表，但运行此命令时出错

错误：

CREATE TABLE `DB`.`ORDER` (
    `oid`               INT NOT NULL UNIQUE AUTO_INCREMENT,
    `createdAt`         TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    `oValue`            FLOAT NOT NULL,
    `no`                INT NOT NULL,
    `qty`               INT NOT NULL,
    `status`            VARCHAR(20) NOT NULL,
    `refundStatus`      VARCHAR(10),
    `refundId`          INT,
    `paymentStatus`     VARCHAR(10),
    `paymentId`         INT,
    `aid`               INT,
    PRIMARY KEY(`oid`),
    FOREIGN KEY `aid` REFERENCES ADDR(`aid`)
)
ENGINE = InnoDB;

我无法理解为什么在这种情况下会发生这种情况，而在其他情况下不会发生这种情况。

替换：

CREATE TABLE `DB`.`ORDER` (
    `oid`               INT NOT NULL UNIQUE AUTO_INCREMENT,
    `createdAt`         TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    `oValue`            FLOAT NOT NULL,
    `no`                INT NOT NULL,
    `qty`               INT NOT NULL,
    `status`            VARCHAR(20) NOT NULL,
    `refundStatus`      VARCHAR(10),
    `refundId`          INT,
    `paymentStatus`     VARCHAR(10),
    `paymentId`         INT,
    `aid`               INT,
    PRIMARY KEY(`oid`),
    FOREIGN KEY `aid` REFERENCES ADDR(`aid`)
)
ENGINE = InnoDB
MySQL said: Documentation

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'REFERENCES ADDR(`aid`)
)
ENGINE = InnoDB' at line 14

与：

或使用官方标准SQL语法：

---

需要外键列周围的括号

外键（aid）引用

我在其他查询中没有注意到括号。非常感谢

FOREIGN KEY `aid` REFERENCES ADDR(`aid`)

FOREIGN KEY (`aid`) REFERENCES ADDR(`aid`)

constraint fk1 FOREIGN KEY (`aid`) REFERENCES ADDR (`aid`)