MariaDB

Question

所以我有这个代码：

基本上，我希望能够在不需要评论的情况下插入任何类型的评级。但是，除非留下评级，否则不能留下评论。例如，insert into movie_rating(movie_quality_rating) values(1); 将产生此错误：ERROR 4025 (23000): CONSTRAINT movie_rating.theatre_food_comment failed for test_db.movie_rating.

这是我想要完成的逻辑（评级必须与其相关评论相关。例如电影评论与电影评级：

rating without comment = yes
comment without ratting = no
comment with rating = yes

抱歉，如果我浪费了任何人的时间，但我已经坚持了好几天，而且我几乎是一个菜鸟，并尝试到处搜索，但这是我最后的选择。我感谢任何帮助。谢谢。

Answer 1

使用table级检查约束来测试多列。

CREATE TABLE movie_rating (
  customer int NOT NULL AUTO_INCREMENT,
  
  movie_quality_rating int(1) CHECK (movie_quality_rating between 1 and 10),
  movie_quality_comment varchar(255),
  
  theatre_food_rating int(1) CHECK (theatre_food_rating between 1 and 10),
  theatre_food_comment varchar(255),
  
  overall_rating int(1) CHECK (overall_rating between 1 and 10),
  overall_comment varchar(255),

  CHECK (movie_quality_comment IS NULL OR movie_quality_rating IS NOT NULL),
  CHECK (theatre_food_comment IS NULL OR theatre_food_rating IS NOT NULL),
  CHECK (overall_comment IS NULL OR overall_rating IS NOT NULL),
  PRIMARY KEY (customer)
);

MariaDB - 无法让我的检查约束有效工作

MariaDB - Can't get my check constraint to work effectively

mysql