6 | Paths and Types in JPQL and Criteria API, a NullPointerException is thrown on any attempt to access a field or a method via a null reference. In JPQL |
6 | What is the Java Persistence API (JPA)?The Java Persistence API (JPA) is a standard API for accessing databases from within Java applications. The main advantage of JPA over JDBC (the older Java API for interacting with databases) is that in JPA data is represented by classes and objects rather than by tables and records as in JDBC |
6 | JPA Named Queries, you may introduce classes to ObjectDB before accessing named queries, by using the JPA 2 Metamodel interface |
4 | javax.persistence.EntityManager Metamodel getMetamodel() Return an instance of Metamodel interface for access to the metamodel of the persistence unit. Return an instance of Metamodel interface for access to the metamodel ... accessed. (The persistence provider runtime is permitted to throw the EntityNotFoundException |
4 | javax.persistence.AccessType> Is used with the Access annotation to specify an access type to be applied to an entity class ... See Also: Access AccessType FIELD Field-based access is used. Field-based access is used. Since: JPA 2.0 AccessType PROPERTY Property-based access is used. Property-based access is used. Since: JPA 2.0 |
1 | Step 5: Add a JSP Page (to prevent direct access to the JSP bypassing Spring). Enter guest as the jsp file name - use exactly |
1 | Step 3: Define a Spring DAO ComponentOperations on the database will be performed by an instance of a Data Access Object (DAO) that we will define in this step as a Spring MVC component: Open the [New Java Class] dialog box by right clicking the guest package node (in the [Package Explorer] window) and selecting New > Class |
0 | What is the Java Data Objects (JDO)?The Java Data Objects (JDO) is another standard for accessing persistent data in databases, using plain old Java objects (POJO) to represent the object model. Unlike Java Persistence API (JPA), which is designated to be used with relational databases, JDO is designated to be used |
0 | javax.jdo.JDOEntityManager() Return an instance of Metamodel interface for access to the metamodel of the persistence unit. Return an instance of Metamodel interface for access to the metamodel of the persistence unit. Returns ... . It is an implementation decision whether to access the data store, if required to determine the exact class |
0 | javax.jdo.spi.PersistenceCapable to LOAD_REQUIRED, then the fields in the default fetch group cannot be accessed for read or write ... fetch group cannot be accessed for read or write without notifying the StateManager. Since: JDO 1.0 ... can be accessed for read without notifying the StateManager. If jdoFlags is set to READ_OK, then the fields |
