By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement . We’ll occasionally send you account related emails.

Issue seems to have started with Spring Boot 2.6.3.

When a JpaRepository interface defines a query created by a method name that returns a projection the application will fail to start with the error below.

Failed to create query for method public abstract com.bug.demo.bugdemo.AgeProjection com.bug.demo.bugdemo.PersonRepository.findByFirstNameIgnoreCase(java.lang.String)! null; nested exception is java.lang.IllegalArgumentException: Failed to create query for method public abstract com.bug.demo.bugdemo.AgeProjection com.bug.demo.bugdemo.PersonRepository.findByFirstNameIgnoreCase(java.lang.String)! null

Repository:
`public interface PersonRepository extends JpaRepository<PersonEntity, Integer> {

Optional<AgeProjection> findByFirstName(String firstName);
Adding a @query annotation to the method with the JPQL query below will successfully execute and return the projection.
`public interface PersonRepository extends JpaRepository<PersonEntity, Integer> {
@query("select p from PersonEntity p where p.firstName = ?1")

Optional findByFirstName(String firstName);
Entity class:

`@Entity

public class PersonEntity {

private Integer id;
private String firstName;
private String lastName;
private Integer age;
// getters/setters

Age Projection:

public interface AgeProjection { Integer getAge(); }