Question

使用Spring Boot，使用Spring Data JPA和H2内存数据库进行映射多对多关系的过程。

我有两张实体书和书。出版商。他们有很多很多关系的地方

创建连接表，将Book_Id和Publisher_id作为外键存储在book_publisher表中，如下所示。

create table book_publisher 
(
  book_id number not null,
  publisher_id number not null,
  PRIMARY KEY (book_id, publisher_id),
  CONSTRAINT fk_bookpublisher_book FOREIGN KEY (book_id) REFERENCES CURRENCY (id) ON DELETE CASCADE ON UPDATE CASCADE,
  CONSTRAINT fk_bookpublisher_publisher FOREIGN KEY (publisher_id) REFERENCES VENUE (id) ON DELETE CASCADE ON UPDATE CASCADE
 );

我没有为book_publisher表编写域类。

但我得到了：

org.h2.jdbc.JdbcSQLException：找不到表“BOOK_PUBLISHERS”; SQL 声明：插入book_publisher（book_id，publisher_ID）值（？，？）[42102-191]“在书本对象（书籍类所在的地方）发布者对象为“SET”变量

如何解决此错误？

Answer 1

如果您正在运行您提到的创建脚本，它将在表CURRENCY和VENUE之间创建many_to_many关系。所以我想说你分享的代码片段是错误的，这可能就是为什么没有成功创建表BOOK_PUBLISHER的原因。

创建many_to_many关系的正确SQL代码（在表BOOK和PUBLISHER之间）应该是：

create table book_publisher 
(
  book_id number not null,
  publisher_id number not null,
  PRIMARY KEY (book_id, publisher_id),
  CONSTRAINT fk_bookpublisher_book FOREIGN KEY (book_id) REFERENCES BOOK (id) ON DELETE CASCADE ON UPDATE CASCADE,
  CONSTRAINT fk_bookpublisher_publisher FOREIGN KEY (publisher_id) REFERENCES PUBLISHER (id) ON DELETE CASCADE ON UPDATE CASCADE
 );

得到“org.h2.jdbc.JdbcSQLException：表”BOOK_PUBLISHERS“找不到; SQL语句：”

1 个答案: