9/15/2023 0 Comments Hibernate versionsFor example, Adobe integrated Hibernate into version 9 of ColdFusion (which runs on J2EE app servers) with an abstraction layer of new functions and syntax added into CFML. It can also be included as a feature in other programming languages. Hibernate can be used both in standalone Java applications and in Java EE applications using servlets, EJB session beans, and JBI service components. For example, a parent Album class object can be configured to cascade its save and delete operations to its child Track class objects. Related objects can be configured to cascade operations from one object to the other. : 289–293 Lazy loading is the default as of Hibernate 3. Hibernate can be configured to lazy load associated collections. Java generics, introduced in Java 5, are also supported. Ĭollections of data objects are typically stored in Java collection classes, such as implementations of the Set and List interfaces. Hibernate recommends providing an identifier attribute, and this is planned to be a mandatory requirement in a future release. Proper behavior in some applications also requires special attention to the equals(Object obj) and hashCode() methods in the Object classes. : 37–38 The only strict requirement for a persistent class is a no-argument constructor, : 39 though not necessarily public. Hibernate provides transparent persistence for Plain Old Java Objects (POJOs). Without this capability, changing the database would require individual SQL queries to be changed as well, leading to maintenance issues. It generates database independent queries so that there is no need to write database-specific queries. HQL (Hibernate Query Language) is the object-oriented version of SQL. Criteria Query is used to modify the objects and provide the restriction for the objects. Criteria Queries are provided as an object-oriented alternative to HQL. Hibernate provides a SQL inspired language called Hibernate Query Language (HQL) for writing SQL-like queries against Hibernate's data objects. Mapping informs the ORM tool of what Java class object to store in which database table. Mapping is a way of resolving the object–relational impedance mismatch problem. This problem is called " object–relational impedance mismatch". Objects in an object-oriented application follow OOP principles, while objects in the back-end follow database normalization principles, resulting in different representation requirements.
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