Question

当我尝试执行以下sql statemant时，MariaDB会出错： SQL：TRUNCATE $ table CASCADE;

SQLSTATE[42000]: Syntax error or access violation: 1064 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 'CASCADE' at line 1 (SQL: TRUNCATE wortmann_products CASCADE;)

是在MariaDB中删除级联还是在sql语句中出错？

Answer 1

如果您希望级联删除和更新，则必须在创建或更改表时存储定义，并将其应用于允许子记录的键（或关联表中的FK）删除父记录时在关联表中删除。这里有很多资源，我在这里列出了一个：https://mariadb.com/kb/en/the-mariadb-library/foreign-keys/ - 从这个资源中获取的是下面的例子：

 CREATE TABLE author (
     id SMALLINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
     name VARCHAR(100) NOT NULL
 ) ENGINE = InnoDB;

 CREATE TABLE book (
     id MEDIUMINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
     title VARCHAR(200) NOT NULL,
     author_id SMALLINT UNSIGNED NOT NULL,
     CONSTRAINT `fk_book_author`
        FOREIGN KEY (author_id) REFERENCES author (id)
        ON DELETE CASCADE
        ON UPDATE RESTRICT
 ) ENGINE = InnoDB;

MariaDB 10.1截断表级联语法错误

1 个答案: