Brice Roncace Brice Roncace - 7 months ago 220
Java Question

Spring Data JPA: Query by Example?

Using Spring Data JPA can I do a query by example where a particular entity instance is used as the search criteria?

For example (no pun intended), if I have a

Person
entity that looks like:

@Entity
public class Person {
private String firstName;
private String lastName;
private boolean employed;
private LocalDate dob;
...
}


I could find all employed persons with a last name of Smith born on January 1, 1977 with an example:

Person example = new Person();
example.setEmployed(true);
example.setLastName("Smith");
example.setDob(LocalDate.of(1977, Month.JANUARY, 1));
List<Person> foundPersons = personRepository.findByExample(example);

Answer

Spring data relies on top of JPA and EntityManager, not Hibernate and Session, and as such you do not have findByExample out of the box. You can use the spring data automatic query creation and write a method in your repository with the following signature:

List<Person> findByEmployedAndLastNameAndDob(boolean employed, String lastName, LocalDate dob);