How Can I Retrieve the Underlying SQL Query from a Hibernate Criteria Object?

Get SQL queries from Hibernate Criteria (no logging required)

Hibernate Criteria API is a powerful tool for expressing complex queries in an easy-to-understand format. However, it does not provide a direct way to retrieve the actual executed SQL. This can be a problem when you need access to precise SQL queries for debugging or integrating with external systems that require raw SQL.

To solve this problem, you can get the underlying SQL from Hibernate Criteria using:

<code class="language-java">CriteriaImpl criteriaImpl = (CriteriaImpl)criteria;
SessionImplementor session = criteriaImpl.getSession();
SessionFactoryImplementor factory = session.getFactory();
CriteriaQueryTranslator translator = new CriteriaQueryTranslator(factory, criteriaImpl, criteriaImpl.getEntityOrClassName(), CriteriaQueryTranslator.ROOT_SQL_ALIAS);
String[] implementors = factory.getImplementors(criteriaImpl.getEntityOrClassName());

CriteriaJoinWalker walker = new CriteriaJoinWalker((OuterJoinLoadable)factory.getEntityPersister(implementors[0]),
                        translator,
                        factory,
                        criteriaImpl,
                        criteriaImpl.getEntityOrClassName(),
                        session.getLoadQueryInfluencers());

String sql = walker.getSQLString();</code>

This code:

1. Convert Criteria object to CriteriaImpl object.
2. Get SessionImplementor and SessionFactoryImplementor instances.
3. Create CriteriaQueryTranslator for generating SQL queries.
4. Get the implementation class name of the entity being queried.
5. Create a CriteriaJoinWalker, which is responsible for traversing the entity hierarchy and generating SQL queries.
6. Finally, retrieve the SQL string from the CriteriaJoinWalker.

This method gives you access to the SQL queries that Hibernate Criteria will execute, allowing you to troubleshoot issues, debug logs, or integrate with external systems that require raw SQL.

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