50 | Working with JPA Entity ObjectsEntity objects are in-memory instances of entity classes (persistable user defined classes), which can represent physical objects in the database. Managing an ObjectDB Object Database using JPA requires using entity objects for many operations, including storing, retrieving, updating and deleting |
45 | JPA Persistence UnitA JPA Persistence Unit is a logical grouping of user defined persistable classes (entity classes ... is optional when using ObjectDB, but required by JPA. persistence.xml Persistence units are defined in ... to instantiate an EntityManagerFactory in JPA (as explained in the JPA Overview section) requires |
44 | JPA Criteria API QueriesThe JPA Criteria API provides an alternative way for defining JPA queries, which is mainly useful for building dynamic queries whose exact structure is only known at runtime. JPA Criteria API vs JPQL JPQL queries are defined as strings, similarly to SQL. JPA criteria queries, on the other hand |
44 | ObjectDB - Object Database for Java (JPA/JDO) it is the bottleneck in most applications. ObjectDB is extremely fast and much faster than any other JPA solution ... is complex. See JPA benchmark results... Reduce development time. Improve productivity. ObjectDB ... API (JPA). It is the first persistence solution that combined a powerful database with JPA support in |
44 | JPA Entity Fields either the Java transient modifier (which also affects serialization) or the JPA @Transient annotation ... of entity types. Basic - for any other persistable type. In JPA only Basic is optional ... of these annotations, so they are useful only for classes that are also in use with an ORM JPA |
43 | JPA Persistable Types. ObjectDB supports all the JPA persistable types, which are: User defined classes - Entity classes ... ; @Entity public class MyEntity { } Entity Class Requirements A portable JPA entity class ... Superclasses In JPA, classes that are declared as mapped superclasses have some of the features of entity |
43 | JPA 2 AnnotationsJPA defines dozens of annotations that can be divided into the following groups: Annotations for JPA aware classes: Annotations for fields in JPA persistable classes: Annotations for additional JPA configuration: Annotations for JPA lifecycle event callbacks: Java EE container annotations: Many |
43 | Setting and Tuning of JPA Queries of other EntityManager instances). JPA implementations can easily make uncommitted changes visible in simple JPA operations, such as find. However, query execution is much more complex ... order to be visible to the query. Flush policy in JPA is represented by the FlushModeType enum |
42 | JPA Metamodel APIThe JPA Metamodel API, which is introduced in JPA 2.0, enables examining the classes, fields ... of the JPA Metamodel API is: Types (mainly classes) and attributes (persistent field and properties ... : The JPA Metamodel API may optionally be used with the JPA Criteria API. Many of the interfaces in |
42 | Query Parameters in JPA (:) followed by a valid JPQL identifier that serves as the parameter name. JPA does not provide an API ... . Criteria Query Parameters In a JPA query that is built by using the JPA Criteria API - parameters (as ... of which are overridden in TypedQuery. That large number of methods is not typical to JPA |
