= 5.3 Migration Guide :toc: This guide discusses migration from Hibernate ORM version 5.2 to version 5.3. For migration from earlier versions, see any other pertinent migration guides as well. == Background Hibernate 5.3 adds support for the JPA 2.2 specification == Known changes === Changes to positional query parameter handling This really breaks down into 2 related changes: * Support for JDBC-style parameter declarations in HQL/JPQL queries has been removed. This feature has been deprecated since 4.1 and removing it made implementing the second change, so we decided to remove that support. JDBC-style parameter declaration is still supported in native-queries. * Since JPA positional parameters really behave more like named parameters (they can be repeated, declared in any order, etc.) Hibernate used to treat them as named parameters - it relied on Hibernate's JPA wrapper to interpret the JPA setParameter calls and properly handle delegating to the named variant. This is actually a regression in 5.2 as it causes `javax.persistence.Parameter#getPosition` to report `null`. For JDBC-style parameter declarations in native queries, we have also moved to using one-based instead of zero-based parameter binding to be consistent with JPA. That can temporarily be reverted by setting the `hibernate.query.sql.jdbc_style_params_base` setting to `true` which reverts to expecting zero-based binding. === Change in the `@TableGenerator` stored value In order to be compliant with the JPA specification, the sequence value stored by Hibernate 5.3 in the database table used by the `javax.persistence.TableGenerator` is the *last* generated value. Previously, Hibernate stored the *next* sequence value. For backward compatibility, a new setting called `hibernate.id.generator.stored_last_used` was introduced, which gives you the opportunity to fall back to the old Hibernate behavior. [NOTE] ==== Existing applications migrating to 5.3 and using the `@TableGenerator` have to set the `hibernate.id.generator.stored_last_used` configuration property to `false`. ==== === Query parameters Method `org.hibernate.type.Type getType()` in `org.hibernate.query.QueryParameter` was renamed to `getHibernateType()`. This was done in order to allow for the re-introduction of `Class getType()` in a sub-interface, `org.hibernate.procedure.ParameterRegistration`. That second method had been removed in 5.2, breaking compatibility with 5.1. === Second-level cache provider SPI changes Hibernate's second-level cache SPI needed to be redesigned to match with expectations between Hibernate and the various caching providers. And the SPI did not really clarify the intention. These mis-matched expectations certainly had the potential to lead to bugs. Although it was originally slated for 6.0 to delay the SPI changes, we decided to back-port the work to 5.3 to address a number of bugs that could have been avoided with a clarified SPI. The changes also allow the caching providers to perform serious optimizations based on the users configuration of domain data caching in Hibernate. Details can be seen on the https://hibernate.atlassian.net/browse/HHH-11356[HHH-11356] Jira issue One potential upgrade concern is any custom `org.hibernate.cache.spi.QueryCacheFactory` implementations. `org.hibernate.cache.spi.QueryCacheFactory` was meant as a means to allow service providers the ability to define query result caching, generally with more stale-tolerant query result invalidation handling. However, the contract also bound it to the old second level cache contracts so they had to be updated. Its responsibilities also changed so we also decided to "rename it" to `org.hibernate.cache.spi.TimestampsCacheFactory` Another specific change to be aware of is accessing cache entries via `SecondLevelCacheStatistics#getEntries` and `NaturalIdCacheStatistics#getEntries`. These methods have been deprecated, however the new caching SPI does not really require caching providers to support this. As of 5.3 these methods inherently return an empty Map (`Collections#emptyMap`). This has always been something that providers did not implement "correctly" anyway === Statistics changes The change for HHH-11356 required changes in its consumers. One such consumer is the Hibernate Statistics system.... === Native (non-JPA) Pagination changes When hibernate-entitymanager module was merged into hibernate-core in Hibernate ORM 5.2, the contracts for the following pre-existing `org.hibernate.Query` methods were changed to be specified by JPA `javax.persistence.Query` methods: `getFirstResult()`, `setFirstResult(int)`, `getMaxResults()`, and `setMaxResults()`. In 5.3.2, the following methods were temporarily added to http://docs.jboss.org/hibernate/orm/5.3/javadocs/org/hibernate/Query.html[`org.hibernate.Query`] to make it easier to migrate native applications from Hibernate ORM 5.1 to 5.3, and maintain 5.1 pagination behavior: * http://docs.jboss.org/hibernate/orm/5.3/javadocs/org/hibernate/Query.html#setHibernateFirstResult-int-[`setHibernateFirstResult(int)`] behaves the same as the 5.1 version of `setFirstResult()`, with a small difference -- calling `setHibernateFirstResult(int)` with a negative value will result in `getHibernateFirstResult()` returning 0, instead of the negative value. Note that this behavior differs from JPA in that `javax.persistence.Query.setFirstResult(int)` throws `IllegalArgumentException` when called with a negative value. * http://docs.jboss.org/hibernate/orm/5.3/javadocs/org/hibernate/Query.html#getHibernateFirstResult--[`getHibernateFirstResult()`] behaves the same as the 5.1 version of `getFirstResult()`, except for the difference mentioned above when `setHibernateFirstResult(int)` is called with a negative number. This method returns `null` if no value was set via `setHibernateFirstResult(int)` (or `setFirstResult(int)`). Note that this behavior differs from JPA in that `javax.persistence.Query.getFirstResult()` returns 0 when uninitialized. * http://docs.jboss.org/hibernate/orm/5.3/javadocs/org/hibernate/Query.html#setHibernateMaxResults-int-[`setHibernateMaxResults`] behaves the same as the 5.1 version of `setMaxResults()`; setting a value less than or equal to 0 is considered uninitialized, resulting in *no limit* on the number of results. Note that this behavior differs from JPA `javax.persistence.Query.setMaxResults(int)`, which, when called with a negative value, throws `IllegalArgumentException`, and when called with a value of 0, indicates that the query should return *no results*. * http://docs.jboss.org/hibernate/orm/5.3/javadocs/org/hibernate/Query.html#getHibernateMaxResults--[`getHibernateMaxResults`] behaves the same as the 5.1 version of `#getMaxResults`. This method returns `null` if uninitialized or a value less than or equal to 0 was set via `setHibernateMaxResults(int)` (or `setMaxResults(int)`). Note that this behavior differs from JPA in that `javax.persistence.Query.getMaxResults() returns `Integer.MAX_VALUE` when uninitialized. These methods are deprecated, and will be removed in a future version. To be portable with future Hibernate versions, applications should be changed to use the JPA methods. === Drop hibernate-infinispan module Support for using Infinispan as a Hibernate 2nd-level cache provider has been moved to the Infinispan project so the `hibernate-infinispan` module has been dropped. A relocation pom which is pointing to `org.infinispan:infinispan-hibernate-cache` dependency is still generated, therefore, avoiding the need of updating any library dependency. [WARN] ==== The relocation pom may be dropped in a future release. ==== === EnhancementTask changes The API of the `org.hibernate.tool.enhance.EnhancementTask` Ant task was changed, specifically the `#addFileset` method was dropped in favor of `#setBase` and `#setDir` See details on the https://hibernate.atlassian.net/browse/HHH-11795[HHH-11795] Jira issue. The main gist is that EnhancementTask was fixed (through a contribution) to actually work with `Enhancer` from `BytecodeProvider`. Previously it had not. And part of fixing that required this change. === Many-to-one association in embeddable collection elements and composite IDs A bug introduced in 4.3 caused many-to-one associations in embeddable collection elements and composite IDs to be eagerly fetched, even when explicitly mapped as lazy. This bug does not affect many-to-one associations that are not in a composite ID or embeddable collection element. In 5.3.2, this bug was fixed. As a result, such associations will be fetched as specified by their mappings. Many-to-one associations mapped by using native HBM xml are lazy by default. In order to keep the associations eager in 5.3.2 and later, mappings will need to explicitly specify that they are non-lazy. When mapped with annotations, many-to-one associations use `FetchType.EAGER` by default. Starting in 5.3.2, if an association is mapped with `FetchType.LAZY`, the assocation will be lazily fetched, as expected. See details on the https://hibernate.atlassian.net/browse/HHH-12687[HHH-12687] Jira issue. === JpaIntegrator removed JPA and native implementations of Hibernate event listeners were unified (see https://hibernate.atlassian.net/browse/HHH-11264) making the `org.hibernate.jpa.event.spi.JpaIntegrator` no longer needed. [NOTE] ==== Existing applications migrating to 5.3 with classes extending `org.hibernate.jpa.event.spi.JpaIntegrator` have to change these classes to implement the `org.hibernate.integrator.spi.Integrator` interface. ==== === 5.3 -> 6.0 compatibility changes The original driving force behind these series of changes is an effort to be as proactive as possible about designing compatibility between 5.3 and 6.0. ==== Type system changes Use of NavigableRole, back-ported from 6.0 rather than plain String