GORM一对多：用给定的多个过滤一个

Question

In this link

一对多的关系是：

    class Author {
           static hasMany = [books: Book]
           String name 
     }

如果我们不在Book中指定belongsTo，即

class Book {
    String title
}

如何使用给定的书籍过滤作者。

def books=[book1,book2,book3]

Answer 1

您可以使用create criteria来获取作者：

    def bookList = //some book list
    def authors = Author.createCriteria().list {
        books {
            'in'('title', bookList*.title)
        }
    }*.name
    println "Authors = ${authors}"

Answer 2

我更喜欢HQL。

Author.executeQuery("select a from Author a join a.books as b where b in (:bookList)", [booklist: books])