CREATE TABLE movie (
ID int PRIMARY KEY,
name varchar2(50) NOT NULL
);
CREATE TABLE length (
ID int PRIMARY KEY REFERENCES movie(ID) ON DELETE CASCADE,
length int NOT NULL
);
于是,我就从两个删除值:
delete from movie where ID=1;
,但得到的错误:
"attempted to delete a parent key value that had a foreign dependency."
为什么如果我使用ON DELETE CASCADE?
实际使用哪些DBMS? varchar2不是有效的sql server数据类型。这是Oracle吗? –
对不起,是的,这是Oracle(SQL Developer) – Linz
'CASCADE'选项在另一个方向上工作。如果从长度删除,它将删除子表上的引用行。检查关系定义。 – Alfabravo