MySQL表創建錯誤1064-找不到原因

Question

我正在嘗試在具有三個外鍵的MySQL數據庫中創建表，但出現錯誤。 這個錯誤對我來說並不明顯，可以使用第三方檢查。

CREATE TABLE `main_message`(
  id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
  strat_key INT NULL,
  task INT NULL,
  user INT,
  comment VARCHAR(255) NOT NULL,
  datestamp DATETIME, 
  FOREIGN KEY strat_key REFERENCES prod_main_strategicdirection(id) ON UPDATE CASCADE ON DELETE CASCADE,
  FOREIGN KEY task REFERENCES main_task(id) ON UPDATE CASCADE ON DELETE CASCADE,
  FOREIGN KEY user REFERENCES prod_auth_user(id) ON UPDATE CASCADE ON DELETE CASCADE,
) ENGINE = INNODB;

根據輸出，我收到錯誤消息

You have an error in your SQL syntax; check the manual that corresponds to your 
MariaDB server version for the right syntax to use near ' foreign key strat_key
references prod_main_strategicdirection(id) on update cas'

在第一次外鍵聲明之后

FOREIGN KEY strat_key REFERENCES prod_main_strategicdirection(id)

但我看不出導致錯誤的原因。

Answer 1

您忘記了FOREIGN KEY上的括號，並在結束前的最后一個CASCADE之后刪除了逗號)

CREATE TABLE `main_message`(
  id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
  strat_key INT NULL,
  task INT NULL,
  user INT,
  comment VARCHAR(255) NOT NULL,
  datestamp DATETIME, 
  FOREIGN KEY(strat_key) REFERENCES prod_main_strategicdirection(id) ON UPDATE CASCADE ON DELETE CASCADE,
  FOREIGN KEY(task) REFERENCES main_task(id) ON UPDATE CASCADE ON DELETE CASCADE,
  FOREIGN KEY(user) REFERENCES prod_auth_user(id) ON UPDATE CASCADE ON DELETE CASCADE
) ENGINE = INNODB;

現場演示。

使用外鍵約束：

[CONSTRAINT [symbol]] FOREIGN KEY
    [index_name] (index_col_name, ...)
    REFERENCES tbl_name (index_col_name,...)
    [ON DELETE reference_option]
    [ON UPDATE reference_option]

reference_option:
    RESTRICT | CASCADE | SET NULL | NO ACTION