Question

I am asking myself if following query can be mapped by Hibernate Criteria API

SELECT * FROM table_a as a LEFT OUTER JOIN table_b as b ON a.primary_key = b.foreign_key and b.any_column = 'my_value'

Ok, everything except and b.any_column = 'my_value' is not difficult for me. Either using FetchMode.JOIN or addCriteria(…,…).

But the and b.any_column = 'my_value' is producing headaches.

I have tried with embedding:

addCriteria("b", Criteria.LEFT_JOIN).add(Restriction.eq("b.any_column", my_value))

But this is producing:

SELECT * FROM table_a as a LEFT OUTER JOIN table_b as b ON a.primary_key = b.foreign_key WHERE b.any_column = 'my_value'

This is not my purpose and is of course producing different results then my expected query. Can anybody give me a hint how I can tell Hibernate to map to the desired query?

Thanks,
Michael

Answer 1

You will probably need to use the createAlias or the createCriteria method.

public Criteria createAlias(String associationPath, String alias, int joinType, Criterion withClause) throws HibernateException;

public Criteria createCriteria(String associationPath, String alias, int joinType, Criterion withClause) throws HibernateException;

There is a forum discussion that will help you: https://hibernate.onjira.com/browse/HHH-2308

For example:

Criteria criteria = getSession().createCriteria(Table_a.class);
criteria.addAlias("Table_b","joined_alias",CriteriaSpecification.LEFT_JOIN);
criteria.list();