Introduction When using PostgreSQL, it’s tempting to use a SERIAL or BIGSERIAL column type to auto-increment Primary Keys. PostgreSQL 10 also added support for IDENTITY, which behaves in the same way as the legacy SERIAL or BIGSERIAL type. This article will show you that SERIAL, BIGSERIAL, and IDENTITY are not a very good idea when using JPA and Hibernate.
Introduction In this article, we are going to see how @MappedSuperclass can help us reuse the @Id mapping of a JPA and Hibernate entity so that it won’t have to be declared on each and every entity.
Introduction As I already mentioned, you should never use the TABLE identifier generator since it does not scale properly. In this post, I’ll show you why you should not rely on the AUTO GenerationType strategy if you’re Hibernate application uses MySQL.
Introduction As previously explained, the TABLE identifier generator does not scale, so you should avoid id. However, some enterprise applications might need to run on both MySQL (which does not support database sequences), as well as Oracle, PostgreSQL, and SQL Server 2012. This is article is going to explain how easily you can achieve this goal using the JPA mapping overriding.
Introduction The entity identifier can either be manually assigned, or it can be automatically generated by an identity column or a database sequence. In this post, I’ll show you how you can mix the assigned generator with an identity column or a database sequence.
Introduction In my previous post I talked about different database identifier strategies. This post will compare the most common surrogate primary key strategies: IDENTITY SEQUENCE TABLE (SEQUENCE) IDENTITY The IDENTITY type (included in the SQL:2003 standard) is supported by: Oracle 12c SQL Server MySQL (AUTO_INCREMENT) DB2 HSQLDB The IDENTITY generator allows an integer/bigint column to be auto-incremented on demand. The increment process happens outside of the current running transaction, so a roll-back may end-up discarding already assigned values (value gaps may happen). The increment process is very efficient since it uses a… Read More