Jpa namedquery with left join fetch

问题

this is my namedquery:

@NamedQuery( name = "User.findOneWithLists", query = "SELECT u FROM User u " + "LEFT JOIN FETCH u.aTemplates " + "LEFT JOIN FETCH u.bTemplates " + "LEFT JOIN FETCH u.bp " + "LEFT JOIN FETCH u.aCredentials " + "LEFT JOIN FETCH u.st WHERE (st.deleted = false) " + "LEFT JOIN FETCH u.bCredentials " + "LEFT JOIN FETCH u.cl " + "WHERE u.id= :id")

My problem is that I get an error when the application starting:

org.hibernate.hql.internal.ast.QuerySyntaxException: unexpected token: LEFT ....

On the st side there is an annotation

@ManyToOne
 @JoinColumn(name = "st_user")
 private User user;

Any idea how can I handle this where clause?

回答1:

Check a SQL syntax, you can't use left join after where clause. If you are looking at the SQL generated form that named query you will see that joined tables in the query the where clause comes after joins and should specify equal condition that links those tables by the keys. The primary key of the main table on the left and the foreign key of the joined table on the right. The joined table is specified by the property of your many-to-one association.

@NamedQuery(
    name = "findOneWithLists",
    query = "from Table t left join User u where u.id= :id"
)

回答2:

For join conditions Hibernate provides the with keyword, even before JPA 2.1.

The relevant part of your query thus would look like this:

SELECT u FROM User u  ... LEFT JOIN u.st WITH st.deleted = false

I'm not sure about LEFT JOIN FETCH u.cl with u.id= :id but if I remember correctly, that's not as easy and might have to be resolved with an adapted join and u.ui = :id in the where condition.

LEFT JOIN FETCH u.st WITH st.deleted = false`

This is not supported, since you can't do a partial fetch.

来源：https://stackoverflow.com/questions/24862058/jpa-namedquery-with-left-join-fetch

标签

java

hibernate

jpa

annotations

named-query