These databases do not conform to the tabular relations maintained by traditional Relational Database Systems (RDMS) like PostgreSQL and maintain different mechanics for storage and retrieval of data.Īs of version 2.4, EclipseLink has support for the NoSQL databases MongoDB & Oracle NoSQL. NoSQL databases have surged in popularity due to the tremendous demand for horizontal scalability for clusters of servers. One of the most interesting features, however, is its ability to talk to NoSQL databases. Amongst others, it also implements JAXB, JCA, & SDO. Other Features of EclipseLinkĮclipseLink is much more than a simple JPA implementation.
This syntax is different from the typical SQL syntax used directly against databases. The same ‘l’ is then SELECTed to assign to the LargeCities List variable to get our resultset. Also, an identification variable ‘l’ is assigned to the LargeCities entity. This is because EclipseLink is looking at our entity and then mapping it to the database based on persistence.xml rather than looking directly at the database. Notice the usage of ‘LargeCities’ rather than ‘largecities’, as is the name of the table we created.
You can create the entity using JPA’s standard and (and other) annotations: import import public class LargeCities īesides the steps mentioned above, the additional thing of significance in this code is how the query is created. This makes the implementation details quite similar to those already described in a preceding Hibernate blog.įor the illustration below, we will continue using the ‘largecities’ example with table structure: postgres=# \d largecities Table "public.largecities" Column | Type | Modifiers -+-+- rank | integer | not null name | character varying(255) | Indexes: "largecities_pkey" PRIMARY KEY, btree (rank) 2.1 Creating an Entity Like Hibernate, EclipseLink is also fully JPA 2.0 compliant. The EclipseLink project provides a proven, commercial quality persistence solution that can be used in both Java SE and Java EE applications.ĮclipseLink is open source and is distributed under the Eclipse Public License. The project delivers an open source runtime framework supporting the Java Persistence API standards. It is based on the TopLink project from which then Oracle contributed code to the EclipseLink project.