Peter Lundgren Peter Lundgren - 6 months ago 16
Java Question

Unexpected empty result using spring query method

I am building an application with a REST API using spring boot and JPA connected to a MySQL database. To search for names in the User class I have implemented a query method:

List< User > findByFirstnameLike( String name );


This method only returns a result on an exact match, which is not what I wanted. Have I misunderstood something about its use?

The repository interface:

public interface UserRepository extends JpaRepository<User, Long> {

public List< User > findByFirstname( String name );

public List< User > findByFirstnameLike( String name );
}


The service bean method:

@Override
public List<User> findByFirstNameLike(String name) {
logger.info( "searching for first name: {}", name);
List< User > ret = userRepo.findByFirstnameLike(name);

if( null == ret ){
logger.info("No list returned from search");
}
else{
logger.info( "List size = {}", ret.size() );
}

return( ret );
}


The REST interface method:

@RequestMapping(
value="/{firstName}",
method=RequestMethod.GET,
produces=MediaType.APPLICATION_JSON_VALUE )
public ResponseEntity< List< User > > SearchForUserByFirstName( @PathVariable( "firstName" ) String firstName ){
return( new ResponseEntity< List< User > >( userService.findByFirstNameLike( firstName ), HttpStatus.OK) );
}


Entity class:

@Entity
public class User {

public enum Department {
BS, BA, BT, BD, UX, SALES
}

@Id
@GeneratedValue
private Long id;

private String firstname;

private String lastname;

private String email;

private String phone;

private Department department;


So... having a user in the database with the name "Adam", the query method returns an empty list for any string except for "Adam".

Edit 2:
After turning on show SQL and inserting an object to the database, I search for a part of the first name and yield this output and an empty List:

searching for first name: dam <-- This is the log print
Hibernate: select user0_.id as id1_6_, user0_.department as
departme2_6_, user0_.email as email3_6_, user0_.firstname as
firstnam4_6_, user0_.lastname as lastname5_6_, user0_.phone as
phone6_6_ from user user0_ where user0_.firstname like ?


The searhing for an exact match which returns an array with one object:

searching for first name: Adam
Hibernate: select user0_.id as id1_6_, user0_.department as
departme2_6_, user0_.email as email3_6_, user0_.firstname as
firstnam4_6_, user0_.lastname as lastname5_6_, user0_.phone as
phone6_6_ from user user0_ where user0_.firstname like ?

Answer

Try to use findByFirstnameContaining instead of findByFirstnameLike.

I am not sure how like is interpreted. But the docs says:

Keyword     | Sample                    | JPQL snippet

Containing  | findByFirstnameContaining | … where x.firstname like ?1 (parameter bound wrapped in %)

And I suppose you want to search for %dam%.

If you want to bound the wildcard at the beginning or ending this is also possible: findByFirstnameStartingWith or findByFirstnameEndingWith.