The Many-To-Many annotation is one of the most important annotations provided by the EclipseLink – JPA. It defines a many-valued association with ManyToMany multiplicity (See single-valued multiplicity and different kind of many-valued multiplicity). A newly concept has introduced such as (JoinTable) as well as a new annotation like (@JoinTable) when we are coming to introduce …
EclipseLink
EclipseLink / JPA Annotations – @OneToMany and @ManyToOne
The OneToMany and ManyToOne annotations are two major JPA annotations that are used for defining two different kinds of associations. The OneToMany annotation define a many-valued association with one-to-many multiplicity, whereas the ManyToOne annotation defines a single-valued association to another entity that has many-to-one multiplicity. The Multiplicity concept seems ambiguous, but it simply tells you the …
EclipseLink Tutorials
EclipseLink is reference implementation for the Java Persistence API (JPA) specification. This project is maintained and supported by the Eclipse Open Source foundation. EclipseLink not only supports the JPA standards, it also supports the following open source standards: Java Persistence API (JPA) Java Architecture for XML Binding (JAXB) Java Connector Architecture (JCA) Service Data Objects …
EclipseLink / JPA Annotations – @OneToOne
OneToOne annotation is one of the annotations that are used for defining a single-valued association to another entity that has one-to-one multiplicity. The multiplicity concept seems ambiguous but it simply tells you the maximum and minimum allowed members of the set. It is a UML design concept for defining the association relationship, in one-to-one case …
EclipseLink / JPA – com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column
This post explains the common exception thrown in your eclipselink or JPA program when you miss the @JoinColumn annotation to refer the foreign key value. @JoinColumn is very important, cause it is used to indicate that there is a Joining at the annotated property, where the persistence implementation will take care of and consider the …
EclipseLink – JPA Annotations
Have you ever been standing up close to an article that list most of the annotations that are used by the EclipseLink – JPA API? The EclipseLink provides many annotations covering the persistence into databases. But when we are coming into use of these annotations, we have already faced a big obstacles while remembering those …
EclipseLink – javax.persistence.PersistenceException : No Persistence provider for EntityManager
This post provides possible exception while doing the JPA programming and the suggested solution for resolving the exception. This post will solve the issue that can be happened while the JPA implementation trying to get a persistence provider. The exception explained in this post thrown when you have not configured properly the persistence unit name in …
EclipseLink – JPA Fields Annotations – @Basic and @Transient
As mentioned earlier, EclipseLink – JPA is a persistence service, provides a mechanism to communicate with a different database vendors. That type of communication has been achieved through what has become known as annotation-based configuration, which is considered as an alternative way for doing a configuration rather than the XML. The XML-based configuration remains one …