How to merge entity collections with JPA and Hibernate
Introduction In this article, you are going to learn why overwriting entity collections is an anti-pattern and how you can merge collections both effectively and efficiently with JPA and Hibernate. The reason I decided to write this article is that I’ve been this question asked over and over and over again.
How to map java.time Year and Month with JPA and Hibernate
Introduction In this article, we are going to see how you can map the java.time.Year and java.time.Month with both JPA and Hibernate. As explained in this article, JPA 2.2 supports LocalDate, LocalTime, LocalDateTime, OffsetTime, OffsetDateTime from the java.time package. Hibernate has been supporting the Java 8 Date/Time classes since 5.0 via the hibernate-java8 dependency, but since version 5.2, this dependency was merged with hibernate-core so you get the Duration, Instant and ZonedDateTime types in addition to the ones supported by JPA 2.2. However, neither JPA nor Hibernate supports the java.time.Year type out-of-the-box…. Read More
How to map the Java YearMonth type with JPA and Hibernate
Introduction In this article, we are going to see how you can map a java.time.YearMonth with both JPA and Hibernate. As I explained in this article, JPA 2.2 supports the following Date/Time types introduced in Java 8: java.time.LocalDate java.time.LocalTime java.time.LocalDateTime java.time.OffsetTime java.time.OffsetDateTime Apart from supporting those, Hibernate supports also: java.time.Duration java.time.Instant java.time.ZonedDateTime However, neither JPA nor Hibernate support the java.time.YearMonth out-of-the-box. As you will see, adding support for java.time.YearMonth is really straightforward for both standard JPA or Hibernate.
Query pagination with JPA and Hibernate
Introduction Inspired by this StackOverflow answer I gave recently, I decided it’s time to write an article about query pagination when using JPA and Hibernate. In this article, you are going to see how to use query pagination to restrict the JDBC ResultSet size and avoid fetching more data than necessary.
Spring read-only transaction Hibernate optimization
Introduction In this article, I’m going to explain how the Spring read-only transaction Hibernate optimization works. After taking a look at what the Spring framework does when enabling the readOnly attribute on the @Transactional annotation, I realized that only the Hibernate flush mode is set to FlushType.MANUAL without propagating the read-only flag further to the Hibernate Session. So, in the true spirit of open-source software developer, I decided it’s time to make a change.
Hibernate performance tuning tips
Introduction In this article, I’m going to summarise the most common Hibernate performance tuning tips that can help you speed up your data access layer. While getting started with JPA and Hibernate is fairly easy, if you want to get the most out of your data access layer, it’s very important to understand how the JPA provider works, as well as the configuration properties that can help you optimize application performance.
The best way to clone or duplicate an entity with JPA and Hibernate
Introduction Have you ever wondered how to clone an entity with JPA or Hibernate? Recently, I stumbled upon this Hibernate forum question and it reminded me that this was a common requirement when working with JPA and Hibernate. In this article, we are going to see the best way to clone a JPA entity with JPA and Hibernate.
How to fix the Hibernate “No Dialect mapping for JDBC type” issue
Introduction Recently, stumbled on this question on the Hibernate forum, and since I’ve been seeing it before on StackOverflow and bumped into it myself while working with JPA and Hibernate, I decided to turn the answer into an article. Therefore, in this article, you are going to find out how you can fix the “No Dialect mapping for JDBC type” Hibernate issue.
How to query by entity type using JPA Criteria API
Introduction Inspired by this Hibernate forum post, I decided to write an article to explain how you can filter by the entity type using Criteria API.
The best way to use SQL functions in JPQL or Criteria API queries with JPA and Hibernate
Introduction When executing an entity query (e.g. JPQL, HQL or Criteria API), you can use any SQL function without having to register it as long as the function is passed directly to the WHERE clause of the underlying SQL statement. However, if the SQL function is used in the SELECT clause, and Hibernate has not registered the SQL function (be it a database-specific or user-defined function), you will have to register the function prior to using it in an entity query. In this article, you are going to learn various ways to… Read More
