MySQL 多對多關系的 CREATE TABLE 錯誤

Question

我對簡單的 CREATE TABLE 查詢有疑問。 我在多對多關系中有兩個表“‘resort’（帶有 resortID 和 resortName）和‘season’（帶有 resortID 和 resortName）。我正在嘗試使用以下兩個查詢之一創建連接表 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
);

這兩個查詢都給我一個錯誤，上面寫着（在這種情況下是第二個查詢的情況）： "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" 。

我究竟做錯了什么？ 這讓我很頭疼，因為我就是看不出錯誤的原因。

如果我簡單地做

CREATE TABLE resort_season (
resortID MEDIUMINT UNSIGNED NOT NULL,
seasonID MEDIUMINT UNSIGNED NOT NULL,
PRIMARY KEY (resortID, seasonID) NOT NULL
);

然后它工作正常並創建了表。 我不確定這張表是否會有效地引用表格度假村和季節。

Answer 1

從主鍵定義中刪除 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)
);