HQL中lements的使用

在传递索引和元素给集合时（elements and indices函数）和传递子查询的结果集时，SQL函数any, some, all, exists, in都是被支持的：

 

可编写如下Hql 语句完成查询：

HQL代码 

select Blog    
from Blog, Book   
where Blog.author in elements(Book.authors)   
    and Book.id=?  

 

对应的Sql近似如下：

Sql代码

select  blog.*
from  blog, book
where  (blog.author  in  ( select  author.authorid
        from  book_author
        where  book.id=book_author.bookid))
    and  book.id=?