Sql 更新或删除违反外键约束
我有两张像下面这样的桌子Sql 更新或删除违反外键约束,sql,postgresql,Sql,Postgresql,我有两张像下面这样的桌子 CREATE TABLE book ( book_id BIGSERIAL PRIMARY KEY, book_special_id character(10) NOT NULL DEFAULT random_string(10) UNIQUE, author_id bigint REFERENCES author(author_id) ON DELETE RESTRICT, category_id bigint REFERENCES c
CREATE TABLE book (
book_id BIGSERIAL PRIMARY KEY,
book_special_id character(10) NOT NULL DEFAULT random_string(10) UNIQUE,
author_id bigint REFERENCES author(author_id) ON DELETE RESTRICT,
category_id bigint REFERENCES category(category_id) ON DELETE RESTRICT,
title text NOT NULL,
subtitle text,
book_text text
);
CREATE TABLE booksubcategory (
booksubcategory_id BIGSERIAL PRIMARY KEY,
book_id BIGSERIAL REFERENCES book(book_id) ON DELETE CASCADE,
subcategory_id BIGSERIAL REFERENCES subcategory(subcategory_id) ON DELETE RESTRICT,
CONSTRAINT booksubcategory_book_id_subcategory_id_key UNIQUE (book_id, subcategory_id)
);
在本例中,book_id列是book表中的主键,而被引用的外键是booksubcategory表中的外键。当我尝试运行以下sql时,收到错误:
ERROR: update or delete on table "book" violates foreign key constraint "booksubcategory_book_id_fkey" on table "booksubcategory"
Detail: Key (book_id)=(888392) is still referenced from table "booksubcategory"
下面是SQL的样子
INSERT INTO book (book_special_id, author_id, category_id, title, subtitle, book_text)
VALUES ("D4jOko2IP0",34, 4, "Book Example", "Book Subtitle", "Some lengthy text")
ON CONFLICT (book_special_id)
DO UPDATE SET author_id=EXCLUDED.author_id, book_id=EXCLUDED.book_id, category_id=EXCLUDED.category_id, title=EXCLUDED.title, subtitle=EXCLUDED.subtitle, book_text=EXCLUDED.book_text;
在这种情况下,sql应该更新列,因为book表中已经存在book\u special\u键
我很熟悉外键约束的更新和删除会因为完整性原因而失败的原因,但在我的例子中,我不是直接更新book_id,而是更新book表中的列。我还在子表中的外键上设置了关于删除级联的。有人能告诉我为什么会遇到此问题吗?插入的行与唯一键special\u book\u id冲突,然后冲突规则尝试更新重复的行
但是,由于冲突而尚未插入且为autogen的新行的值帐簿id是多少?嗯,要么是空的,要么是新的序列号
因此,不管是哪种情况,您都要将book_id更新为null或一个新的序列号,但由于正在消失的旧book_id值具有引用,因此更新失败
删除对列book\u id的更新,它应该可以工作。您的更新会更改行的主键-显然是一个新值,但旧值仍然从booksubcategory表中引用。哦,我明白了。我忘了拆下那条线。我找了好几个小时,这只是一个简单的错误。谢谢你指出这一点。