I am using spring-data-jpa on a spring webmvc project. I am facing an issue using query creation on a Repository of one of my Entities. Below you can see my Entity, my Repository and the Exception.
My Entity:
@Entity
@Table(schema = "mainschema")
@XmlRootElement
public class Municipalperson implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Basic(optional = false)
@Column(nullable = false)
private Integer id;
@Basic(optional = false)
@Column(name = "municipal_id", nullable = false)
private Integer municipal_id;
@Basic(optional = false)
@Column(nullable = false, length = 60)
private String firstname;
public Municipalperson(Integer id, Integer municipal_id, String firstname) {
this.id = id;
this.municipal_id = municipal_id;
this.firstname = firstname;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public Integer getMunicipal_id() {
return municipal_id;
}
public void setMunicipal_id(Integer municipal_id) {
this.municipal_id = municipal_id;
}
public String getFirstname() {
return firstname;
}
public void setFirstname(String firstname) {
this.firstname = firstname;
}
}
my Repository:
@Repository
public interface MunicipalpersonRepository extends JpaRepository<Municipalperson, Integer> {
List<Municipalperson> findByMunicipal_idOrderByLastnameDesc(int municipal_id);
}
and the exception,
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'municipalpersonRepository': Invocation of init method failed; nested exception is org.springframework.data.mapping.PropertyReferenceException: No property municipal found for type Municipalperson!
I tried to set municipal_id as int, then as Integer and the same for the parameter municipal_id on my Repository, but none worked. Also, I renamed the Repository to findByMunicipalidOrderByLastnameDesc and findByMunicipalIdOrderByLastnameDesc but it didn’t work either.
Finally I renamed the municipal_id to municipalId (underscore removed) and also renamed getters/setters and the Repository (findByMunicipalIdOrderByLastnameDesc) and the issue was resolved.
My question is why this is happening?
Answer
The underscore _ is a reserved character in Spring Data query derivation (see the reference docs for details) to potentially allow manual property path description. So there are two options you have:
- Stick to the Java naming conventions of using camel-case for member variable names and everything will work as expected.
- Escape the
_by using an additional underscore, i.e. rename your query method tofindByMunicipal__idOrderByLastnameDesc(…).
I’d recommend the former as you’re not going to alienate fellow Java developers :).