If ID is not present then save() is called.In most cases, it is the preferred method to save(). The saveOrUpdate(), as the name implies, works as either save() or update() on the basis of the ID field present in the entity or not.
#UPDATE MULTIPLE ROWS IN HIBERNATE JAVA UPDATE#
Hibernate: update Employee set lastName=? where ID=? 4.
Hibernate: insert into Employee (email, firstName, lastName, ID) values (?, ?, ?, ?) To correctly update an entity, make it persistent first using save() or persist() methods. : The given object has a null identifier:Ĭom. It throws TransientObjectException if there is no identifier associated (transient entity).It executes the SQL UPDATE query for PERSISTENT entities.The update() is pretty much a simpler method. If the strategy is GenerationType.IDENTITY then we will get ConstraintViolationException for duplicate primary key violation.If the strategy is GenerationType.SEQUENCE then a new identifier will be generated and a duplicate record will be inserted into the database.With Detached EntityĪ detached entity already has the identifier associated with it so the behavior of the save() method depends on the ID generation strategy when executing the INSERT query. Hibernate: update Employee set lastName=? where ID=? 2.3. Hibernate: insert into Employee (ID, email, firstName, lastName) values (default, ?, ?, ?) Long id = session.save(employee) Ĭheck out that the second statement is UPDATE query. With Persistent Entityįor PERSISTENT entities, save() works as update() method and executes UPDATE SQL queries. Hibernate: insert into Employee (ID, email, firstName, lastName) values (default, ?, ?, ?) 2.2. This will execute the SQL INSERT statement. EmployeeEntity employee = new id = session.save(employee) This can cause data inconsistency if we forget to flush the changes or some application error happens. Note that if we call save() outside the transaction then associated entities may not be inserted immediately because save() has to return the generated identifier only for the main entity. The save() method returns the generated identifier so it has to immediately execute the SQL INSERT statement ( it does not matter if we are inside or outside of a transaction) because identifiers are generated by the database during the INSERT query execution only. Before persisting the entity, it assigns a generated identifier to the ID field. The save() method is used make a TRANSIENT entity PERSISTENT by associating it with either an.
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