[英]MySQL error on CREATE TABLE for many-to-many relationship
我对简单的 CREATE TABLE 查询有疑问。 我在多对多关系中有两个表“‘resort’(带有 resortID 和 resortName)和‘season’(带有 resortID 和 resortName)。我正在尝试使用以下两个查询之一创建连接表 resort_season:
CREATE TABLE resort_season (
resortID MEDIUMINT UNSIGNED NOT NULL,
seasonID MEDIUMINT UNSIGNED NOT NULL,
FOREIGN KEY (resortID) REFERENCES resort (resortID),
FOREIGN KEY (seasonID) REFERENCES season (seasonID),
PRIMARY KEY (resortID, seasonID) NOT NULL
);
CREATE TABLE resort_season (
resortID MEDIUMINT UNSIGNED NOT NULL FOREIGN KEY REFERENCES resort (resortID),
seasonID MEDIUMINT UNSIGNED NOT NULL FOREIGN KEY REFERENCES season (seasonID),
PRIMARY KEY (resortID, seasonID) NOT NULL
);
这两个查询都给我一个错误,上面写着(在这种情况下是第二个查询的情况): "You have an error in your syntax; check manual....for right syntax to use near'FOREIGN KEY REFERENCES resort (resortID), seasonID MEDIUMINT UNSIGNED NOT NULL F' at line 2"
。
我究竟做错了什么? 这让我很头疼,因为我就是看不出错误的原因。
如果我简单地做
CREATE TABLE resort_season (
resortID MEDIUMINT UNSIGNED NOT NULL,
seasonID MEDIUMINT UNSIGNED NOT NULL,
PRIMARY KEY (resortID, seasonID) NOT NULL
);
然后它工作正常并创建了表。 我不确定这张表是否会有效地引用表格度假村和季节。
从主键定义中删除 NOT NULL -
CREATE TABLE resort_season(
resortID MEDIUMINT UNSIGNED NOT NULL,
seasonID MEDIUMINT UNSIGNED NOT NULL,
FOREIGN KEY (resortID) REFERENCES resort (resortID),
FOREIGN KEY (seasonID) REFERENCES season (seasonID),
PRIMARY KEY (resortID, seasonID)
);
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.