Native SQL query for an Hibernate entity using @Formula results in NullPointerException

问题

I've got an simple Hibernate entity for which I use the @Formula annotion:

    @Id
private Long id;

private String name;

@Formula("(select count(f.*) from foo f where f.id = id)")
private long bar;

When I try to load an entity with a native SQL Query:

EM.createNativeQuery("SELECT f.*, count(something) as bar FROM foo f WHERE f.name = '...'", Entity.class)

I get an NullPointerException:

java.lang.NullPointerException
at org.hibernate.loader.DefaultEntityAliases.intern(DefaultEntityAliases.java:193)
at org.hibernate.loader.DefaultEntityAliases.getSuffixedPropertyAliases(DefaultEntityAliases.java:151)
at org.hibernate.loader.DefaultEntityAliases.determinePropertyAliases(DefaultEntityAliases.java:93)
at org.hibernate.loader.DefaultEntityAliases.<init>(DefaultEntityAliases.java:65)
at org.hibernate.loader.ColumnEntityAliases.<init>(ColumnEntityAliases.java:45)
at org.hibernate.loader.custom.sql.SQLQueryReturnProcessor.generateCustomReturns(SQLQueryReturnProcessor.java:197)
at org.hibernate.loader.custom.sql.SQLCustomQuery.<init>(SQLCustomQuery.java:152)
at org.hibernate.engine.query.NativeSQLQueryPlan.<init>(NativeSQLQueryPlan.java:67)
at org.hibernate.engine.query.QueryPlanCache.getNativeSQLQueryPlan(QueryPlanCache.java:140)
at org.hibernate.impl.AbstractSessionImpl.getNativeSQLQueryPlan(AbstractSessionImpl.java:160)
at org.hibernate.impl.AbstractSessionImpl.list(AbstractSessionImpl.java:165)
at org.hibernate.impl.SQLQueryImpl.list(SQLQueryImpl.java:179)
at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:236)

When I remove the @Formula attribute all works fine.

I found this bug report: BugReport. But for me it's not clear how to solve my problem.

回答1:

Indeed, this seems to be the problem reported in HHH-2225 (that HHH-2536 duplicates). Unfortunately, the issue is not fixed and I'm afraid you'll have to either use HQL or submit a patch (you can start with voting on the issue but I wouldn't expect a fast resolution given that this issue is almost four years old).

回答2:

We could use currentSession.createQuery() instead of currentSession.createSQLQuery(). The query will be slightly different.

http://docs.jboss.org/hibernate/core/3.6/reference/en-US/html/queryhql.html#queryhql-subqueries

回答3:

Simply way , don't use createNativeQuery , just use createQuery .. or make a transiant with getter convat

来源：https://stackoverflow.com/questions/3331529/native-sql-query-for-an-hibernate-entity-using-formula-results-in-nullpointerex

标签

hibernate

formula

native-sql