10 | GROUP BY and HAVING clauses calculations - the GROUP BY functions merely as a DISTINCT operator. For example, the above query ... clause in which all the FROM/WHERE objects (or object tuples) are considered as one group. For example ... methods for setting the GROUP BY and HAVING clauses. For example, the following JPQL query: SELECT c |
10 | ORDER BY clause (JPQL / Criteria API), for example, is invalid because the ORDER BY expression is not part of the results: SELECT c.name FROM ... can order these groups. For example: SELECT c.currency, SUM(c.population) FROM Country c ... methods for setting the ORDER BY clause. For example, the following JPQL query: SELECT c FROM |
10 | Locking in JPA a PESSIMISTIC_READ lock on that database object. For example, consider the following code fragment: em1 ... and locking as one atomic operation. For example, the find method has a form that accepts a lock mode ... . For example: Map<String,Object> properties = new HashMap(); properties.put("javax.persistence.lock |
10 | JPA Exceptions the PersistenceException class. Some specific errors are represented by subclasses of PersistenceException. For example ... ) . For example, if a transaction fails because of an attempt to store a new entity object with a primary ... to retrieve entity objects from the database. For example, when a required entity object is not found: or |
10 | JPA Primary Key above. For example, the primary key of the following Project entity class consists of two fields: @Entity @IdClass ... key) of a specified managed entity object. For example: PersistenceUnitUtil util = emf ... . This is especially useful when using queries that return large result sets. As an example, consider a real time |
8 | JPA Entity Fields provider (such as Hibernate) or to change default field settings. For example: @Entity public class ... (the Employee class in our example) is the owner. Only changes to the owner side affect the database |
8 | Database Replication and Clustering, only the first URL (the master database in this example) is used. But when the first URL ... this example to the slave database) until the first URL becomes available again. |
8 | Detached Entity Objects address; : } In the example above, the Employee entity class contains an address field ... address; : } In the example above, the Employee entity class contains an address field |
8 | Is ObjectDB better than competing object databases? supporting features that are usually available only in relational databases. For example, most object ... that an essential feature is missing. For example, some competing products do not support aggregate |
1 | [ODB1] Chapter 4 - JDO Metadata if it is also persistent. In the above metadata example, class C is probably defined as a subclass of class B ... by field f0, changes a field that is transient by default to persistent. For example, a field ... modifier (for example, when a field has to be persistent in serialization). A field that is declared |
