ByThorben JanssenMost databases offer many proprietary features besides the known SQL standard. One example is PostgreSQL’s JSONB data type which allows you to store JSON documents efficiently in a database column. You could, of course, store the JSON document in a text column. That column type is part of the SQL standard. Hibernate and all other…
ByThorben JanssenMost developers prefer numerical primary keys because they are efficient to use and easy to generate. But that doesn’t mean that a primary key has to be a number. UUIDs, for example, have gained some popularity over recent years. The main advantage of a UUID is its (practical) global uniqueness which provides a huge advantage…
ByThorben JanssenHibernate implements JPA’s standardized constructor expressions and @SqlResultSetMappings to map the results of your queries. And it also supports proprietary ResultTransformers. They provide a powerful and flexible way to map the result of your JPQL, Criteria, and native SQL query to a specific object structure. This can be entity or DTO objects, java.util.List or java.util.Map…
ByThorben JanssenJPA and Hibernate provide a default mapping that maps each entity class to a database table with the same name. Each of its attributes gets mapped to a column with the same. But what if you want to change this default, e.g., because it doesn’t match your company’s naming conventions? You can, of course, specify…
ByThorben JanssenDatabases support various data types to store date and time information. The most commonly used ones are: DATE to save a date without time information, TIME to store a time without a date, and TIMESTAMP to store date and time information. You can map all of them with JPA and Hibernate. But you need to…