0 
@Entity
@Table(name = "BOOKTEST")
@NamedQueries({@NamedQuery(name = "Booktest.findAll", query = "SELECT b FROM Booktest b"), @NamedQuery(name = "Booktest.findById", query = "SELECT b FROM Booktest b WHERE b.id = :id"), @NamedQuery(name = "Booktest.findByBookName", query = "SELECT b FROM Booktest b WHERE b.bookName = :bookName")})
public class Booktest implements Serializable {
 @ManyToOne
    private Topictest topictestId;   //foreign key
    @JoinColumn(name = "USERTEST_ID", referencedColumnName = "ID")
    @ManyToOne
    private Usertest usertestId;  //foreign key
}

当我执行

session.createCriteria(Booktest.class).createAlias("usertestId", "usertestId",Criteria.LEFT_JOIN) .list();

sql_log 仍然显示select * from booktest,usertest而不是 select * from booktest left join usertest 如何做左连接？

在这两种情况下都尝试了非追随者，但我仍然在没有“左连接”的情况下低于 

Hibernate: select this_.ID as ID13_2_, this_.BOOK_NAME as BOOK2_13_2_, this_.TOP
ICTEST_ID as TOPICTEST4_13_2_, this_.USERTEST_ID as USERTEST3_13_2_, usertestid1
_.ID as ID14_0_, usertestid1_.TOPIC_NAME as TOPIC2_14_0_, usertest4_.ID as ID15_
1_, usertest4_.USER_NAME as USER2_15_1_ from BOOKTEST this_, TOPICTEST usertesti
d1_, USERTEST usertest4_ where this_.TOPICTEST_ID=usertestid1_.ID and this_.USER
TEST_ID=usertest4_.ID(+)
4

2 回答 2

1

尝试这个

session.createCriteria(BookTest.class)
           .createAlias("topictestId", "usertestId")
           .setFetchMode("topictestId",FetchMode.EAGER)
           .list();

理论上这应该可以工作，如果不尝试没有别名的话。

于 2009-11-03T02:54:23.513 回答
1

最后一个功能在新的休眠版本中被废弃。 https://docs.jboss.org/hibernate/orm/5.0/javadocs/org/hibernate/FetchMode.html 使用 FetchMode.JOIN 谢谢

于 2015-08-16T17:37:34.560 回答