是否可以忽略使用 sqlite 插入时的外键冲突？

Question

这是我拥有的两个表的匿名表示：

create table if not exists master_node (
    book_name text primary key on conflict ignore not null
);

create table if not exists category_table (
    book_name text not null,
    category text not null,
    foreign key(book_name) references master_node(book_name) on delete cascade,
    unique(book_name, category) on conflict ignore
);

当我将代码插入表中时：

insert into master_node
    (book_name)
values
    ('Harry Potter'),
    ('Foundation'),
    ('The Catcher in the Rye')

和

insert or ignore into category_table
    (book_name, category)
values
    (Harry Potter', 'Fiction'),
    ('Harry Potter', 'Fantasy'),
    ('Foundation', 'Fiction'),
    ('Foundation', 'Science Fiction'),
    ('The Catcher in the Rye', 'Coming-of-age'),
    ('Moby Dick', 'Adventure')

我收到 [SQLITE_CONSTRAINT] Abort due to constraint violation (FOREIGN KEY constraint failed) 错误，事务被回滚。

我希望通过使用 insert or ignore 我能够简单地跳过违反外键约束的行。我一直无法找到一种方法来获得这种行为。 sqlite 是否提供这样做的方法？

Answer 1

没有 INSERT OR IGNORE 的等效项，它仅适用于违反 UNIQUE 约束和违反 FOREIGN KEY 约束的情况。

作为解决方法，您可以在 INSERT ... SELECT 语句中使用 EXISTS：

WITH cte(book_name, category) AS (
    VALUES 
    ('Harry Potter', 'Fiction'),
    ('Harry Potter', 'Fantasy'),
    ('Foundation', 'Fiction'),
    ('Foundation', 'Science Fiction'),
    ('The Catcher in the Rye', 'Coming-of-age'),
    ('Moby Dick', 'Adventure')
)
INSERT INTO category_table (book_name, category)
SELECT c.book_name, c.category
FROM cte c
WHERE EXISTS (SELECT 1 FROM master_node m WHERE m.book_name = c.book_name)

参见demo。
结果：

> book_name              | category       
> :--------------------- | :--------------
> Harry Potter           | Fiction        
> Harry Potter           | Fantasy        
> Foundation             | Fiction        
> Foundation             | Science Fiction
> The Catcher in the Rye | Coming-of-age

是否可以忽略使用 sqlite 插入时的外键冲突？

Is it possible to ignore foreign key conflicts on insert with sqlite?

sqlite

foreign-keys

constraints

exists

constraintviolationexception