44 | Obtaining a JPA Database Connection, update, and delete should only be performed within an active transaction. Given an EntityManager, em, it is very easy to begin a transaction: em.getTransaction().begin ... that the getTransaction method returns. When a transaction is active you can invoke EntityManager methods |
41 | Storing JPA Entity Objects and changes its state to Managed. The new entity object is stored in the database when the transaction ... field values). A TransactionRequiredException is thrown if there is no active transaction when persist is called because operations that modify the database require an active transaction. If the database |
41 | Database Connection using JPA the content of a database require active transactions. Transactions are managed by an EntityTransaction ... ) must be performed within an active transaction. The EntityTransaction interface represents and manages database transactions. Every EntityManager holds a single attached EntityTransaction instance |
7 | Step 3: Define a Spring DAO Component.transaction.annotation.Transactional; @Component public class GuestDao { // Injected database ... : @Transactional public void persist(Guest guest) { em.persist(guest ... field (because it is annotated with the @PersistenceContext annotation). Handles transactions |
7 | Step 3: Define a Spring DAO Component.TypedQuery; import org.springframework.stereotype.Component; import org.springframework.transaction.annotation.Transactional; @Component public class GuestDao { // Injected database connection: @PersistenceContext private EntityManager em; // Stores a new guest: @Transactional |
4 | Constants.PROPERTY_TRANSACTION_ISOLATION_LEVEL_READ_COMMITTEDStatic Field javax.jdo.Constants String PROPERTY_TRANSACTION_ISOLATION_LEVEL_READ_COMMITTED "javax.jdo.option.TransactionIsolationLevel.read-committed" Since: JDO 2.2 See Also: PersistenceManagerFactory.supportedOptions() |
4 | Constants.PROPERTY_TRANSACTION_ISOLATION_LEVELStatic Field javax.jdo.Constants String PROPERTY_TRANSACTION_ISOLATION_LEVEL "javax.jdo.option.TransactionIsolationLevel" Since: JDO 2.2 |
4 | getRetainValues()Method javax.jdo.Transaction boolean getRetainValues() If true, at commit time instances retain their field values. Returns: the value of the retainValues property Since: JDO 1.0 |
4 | getRestoreValues()Method javax.jdo.Transaction boolean getRestoreValues() Return the current value of the restoreValues property. Returns: the value of the restoreValues property Since: JDO 1.0 |
4 | setRetainValues(retainValues)Method javax.jdo.Transaction void setRetainValues( boolean retainValues ) If true, at commit instances retain their values and the instances transition to persistent-nontransactional. If an implementation does not support this option, a JDOUnsupportedOptionException is thrown. Parameters |
