Resolving the HQL Error: No Data Type for Node in Hibernate

How can I fix the error related to 'No data type for node: org.hibernate.hql.internal.ast.tree.IdentNode' in my HQL query?

artifacts = Artifact.findAll("FROM Artifact WHERE id NOT IN ( SELECT artifact_id FROM Classification WHERE active = 1) AND document_id = :docid",[docid:document.id], [max:limit, offset:startIndex]);

The error 'No data type for node: org.hibernate.hql.internal.ast.tree.IdentNode' typically occurs when Hibernate fails to recognize the identifier you're using in your HQL query, often due to misalignments between the case sensitivity of your column names or mapping definitions. This guide will break down the causes and remedies step by step.

artifacts = Artifact.findAll("FROM Artifact WHERE id NOT IN ( SELECT c.artifactId FROM Classification c WHERE c.active = 1) AND document_id = :docid", [docid: document.id], [max: limit, offset: startIndex]);

Causes

• Incorrect case usage in the HQL query for field names.
• The field reference does not match the naming conventions defined in the Hibernate mapping or entity definition.
• Misconfiguration in entity or field definitions, specifically regarding property names.

Solutions

• Ensure that the names used in HQL queries exactly match the property names defined in the domain model, including case sensitivity. For instance, use '.artifactId' rather than 'artifact_id'.
• Check the mapping configuration in your Classification class to ensure that the identifiers are properly defined and used consistently throughout your queries.
• Review the query to ensure it correctly references the entity's attributes.
• Consider using aliases for your inner queries to avoid conflicts and make the readability better.

Mistake: Using incorrect field names in the HQL query.

Solution: Always cross-check your HQL against the defined fields within your domain model or entity.

Mistake: Omitting necessary aliases in subqueries.

Solution: Use table aliases (e.g., 'c') in your HQL to clarify which fields you're referencing.