How to Replace MySQL's LIMIT Clause in JPQL or HQL?

Alternative to MySQL LIMIT Clause in JPQL or HQL

In Hibernate 3, the equivalent of the MySQL LIMIT clause in HQL is not directly supported. While it was possible in earlier versions of Hibernate, it is no longer a feature.

Historical Note:

In Hibernate 2, the HQL parser did not strictly enforce adherence to standard HQL syntax. This resulted in the ability to include unrecognized fragments, such as the LIMIT clause, within an HQL query. However, with the introduction of an AST HQL parser in Hibernate 3, such non-standard constructs are no longer tolerated.

Solution:

The recommended approach for limiting query results in Hibernate 3 and onwards is to use the setMaxResults() method of the Query interface. This method allows you to specify the maximum number of results to be returned by the query.

To emulate the behavior of the MySQL LIMIT clause, you can use setMaxResults() in conjunction with the setFirstResult() method. For example, to return the first 20 results from a query, you would use the following code:

Query query = session.createQuery("from ATable order by aTableColumn desc");
query.setMaxResults(20);
query.setFirstResult(0);

While setMaxResults() may not be as concise as the LIMIT clause, it provides a consistent and supported mechanism for limiting query results in JPQL and HQL.

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