Prevent changes made to an Entity from going into the DB within an Transaction
Spring data jpa annotations cheat sheet update#
In this case 1 x INSERT and 2 x UPDATE statements are being Transactional Send out changes to the DB within a Transaction In this case 1 x INSERT and 1 x UPDATE statement are being Transactional The EntityManager keeps track of all the changes that are being made to an Entity In a method every set-method results in an update of the row regardless of calling em.merge() on it Reset In-Memory DB after a test method that changes the state of the DirtiesContext createQuery( "select p from Person p", Person. Define multiple named queries on an NamedQuery( name= "find_all_persons", query= "select p from Person NamedQuery( name= "find_all_persons_with_a", query= "select p from Person p where name like 'a%'")
NamedQuery( name= "find_all_persons", query= "select p from Person p") createNamedQuery( "find_all_persons", Person. Find all entities with EntityManager (using JPQL -> It uses entites in its query, not table names) Delete a JPA entity with EntityManager Insert or Update a JPA entity with EntityManager
Spring data jpa annotations cheat sheet code#
It allows us to map our domain model directly to the database structure and then gives us the flexibility of manipulating objects in our code - instead of messing with cumbersome JDBC components like Connection, ResultSet, etc. Show SQL statistics of JPA / Hibernate (e.g. The Java Persistence API (JPA) is the persistence standard of the Java ecosystem. Pretty print the SQL printed on the console Show SQL Statements made with JPA / Hibernate
Public class PersonJpaRepository PersistenceContext
Enable Transaction Management on each Transactional // Public class Team ManyToMany( cascade = ) ĮntityManger = Interface to the PersistenceContext Spring JPA Id The Id annotation can be applied to a member of a class to designate that this member will uniquely identify the entity in the database. Model a m:n relationship where the corresponding relationship record would be deleted when a entity record is Entity Applying the Entity annotation to a class with JPA declares that the class definition will correspond to a database table with a similar name. Delete dependent children, when the parent is going to be deleted (child-entites are orphans (=Waisen) OneToMany( mappedBy= "foo", orphanRemoval= true) websocket WebSocket applications using Spring Framework’s WebSocket. webflux WebFlux applications using Spring Framework’s Reactive Web. security Secured services with Spring Security. Use a database sequence on id Table( name = "ADDRESS") Common starters: web Web applications using Spring MVC (Tomcat embedded) test Spring test using JUnit, Hamcrest and Mockito. Vorteile: - Es werden automatisch Änderungen getrackt.īeim nächsten Transaktions-Commit werden nur die Änderungen in die DB geschrieben.ĭetached - Lazy Loading muss nicht zwangsweise funktionieren Managed - Es gibt einen Entity-Manager, der für dieses Objekt verantwortlich ist: Managed -> query.getSingleResult -> ManagedĮin neu angelegtes Entity Object ist im Zustand "New". Managed -> query.getResultList -> Managed ByteCode Enhancement (default in EclipseLink): Add special logic to the get methods inside the Java Bytecode Proxying the object (default in Hibernate) by creating a Subclass of that object at runtime and overwrite the get methods.Ģ. Two types of Lazy Loading implementationsġ. Lists + Sets fetch type is LAZY by default SomeEntity entity = entityManager.find(SomeEntity.class, fetch type is EAGER by default This is an extremely flexible and powerful feature of Spring Data JPA and it allows you to bootstrap queries without writing the queries themselves, or even implementing any handling logic in the back-end.Transaction Management with an Entity-Mananger: Note: To view this output, you'll have to set the debugging level of MongoTemplate to DEBUG.
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