"Set does NOT contain a certain item" 的 JPA 查询

Question

假设我们有一个 class Person 其中包含 Set<Book> books.

要找到拥有本书"Effective Java"的所有人，您可以这样写：

select p from Person p left outer join fetch p.books as b where b.name='Effective Java'

现在，我怎样才能颠覆这个查询，并找到所有Person 没有这本书？

select p from Person p "where p.books does not contain book b where b.name='Effective Java'"

Answer 1

您可以利用 NOT EXISTS 关键字：

select p 
from Person p
where not exists (
   select b from p.books b where b.name = 'Effective Java'
)

Answer 2

或者

 select p from Person p join p.books b where b.name <> 'Effective Java'

JPA Query for "Set does NOT contain a certain item"