Spring Boot JPA Query Error - "No property '' found for type '' " Exception

I am currently studying an online Spring Boot course working with Spring Data JPA.

My project includes 2 entities: BDProject and BDUser which have a many to one relationship. When attempting to find projects from user id the following exception is displayed.

EXCEPTION

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'BDProjectController': Unsatisfied dependency expressed through field 'bdProjectService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'BDProjectService': Unsatisfied dependency expressed through field 'bdProjectRepository'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'BDProjectRepository': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Failed to create query for method public abstract java.util.List com.project.bdproject.BDProjectRepository.findByUserID(java.lang.String)! No property userID found for type BDProject!

I have spent hours trying to figure out what's causing this exception, but nothing seems to be fixing it.

MY CODE:

Entities

@Entity
public class BDUser {


@Id
private String userID;
private String bdUsername;
private String bdUserEmail;
private String bdUserPassword;

public BDUser(){
}

public BDUser(String userID, String bdUsername, String bdUserEmail, String bdUserPassword) {
    super();
    this.userID = userID;
    this.bdUsername = bdUsername;
    this.bdUserEmail = bdUserEmail;
    this.bdUserPassword = bdUserPassword;
}
// getters and setters...

@Entity
public class BDProject {

@Id
private String proID;
private String proName;
private String proCodeOwner;
private String proIDs;
@ManyToOne
private BDUser bdUser;

public BDProject() {
}

public BDProject(String proID, String proName, String proCodeOwner, String proIDs, String userID) {
    super();
    this.proID = proID;
    this.proName = proName;
    this.proCodeOwner = proCodeOwner;
    this.proIDs = proIDs;
    this.bdUser = new BDUser(userID, "", "", "");
}
// getters and setters...

Controller

@RestController
public class BDProjectController {

@Autowired
private BDProjectService bdProjectService;

@RequestMapping("/bdusers/{userID}/bdprojects")
public List<BDProject> getAllProjects(@PathVariable String proID){
    return bdProjectService.getAllProjects(proID);
}

@RequestMapping("/bdusers/{userID}/bdprojects/{proID}")
public BDProject getProject(@PathVariable String proID){
    return bdProjectService.getProject(proID);
}

@RequestMapping(method= RequestMethod.POST, value="/bdusers/{userID}/bdprojects")
public void addProject(@RequestBody BDProject bdProject, @PathVariable String userID){
    bdProject.setBdUser(new BDUser(userID, "", "", ""));
    bdProjectService.addProject(bdProject);
}

@RequestMapping(method= RequestMethod.PUT, value="/bdusers/{userID}/bdprojects/{proID}")
public void updateProject(@RequestBody BDProject bdProject, @PathVariable String userID, @PathVariable String proID){
    bdProject.setBdUser(new BDUser(userID, "", "", ""));
    bdProjectService.updateProject(bdProject);
}

@RequestMapping(method= RequestMethod.DELETE, value="/bdusers/{userID}/bdprojects/{proID}")
public void deleteProject(@PathVariable String proID){
    bdProjectService.deleteProject(proID);
}

}

Service

@Service
public class BDProjectService {

@Autowired
private BDProjectRepository bdProjectRepository;

public List<BDProject> getAllProjects(String userID){
    List<BDProject> bdProjects = new ArrayList<>();
    bdProjectRepository.findByUserID(userID).forEach(bdProjects::add);
    return bdProjects;
}

public BDProject getProject(String proID){

    return bdProjectRepository.findById(proID).orElse(null);
}

public void addProject(BDProject BDProject){

    bdProjectRepository.save(BDProject);
}

public void updateProject(BDProject BDProject){

    bdProjectRepository.save(BDProject);
}

public void deleteProject(String proID){

    bdProjectRepository.deleteById(proID);
}

}

Repository

public interface BDProjectRepository extends CrudRepository<BDProject, String>{

    public List<BDProject> findByUserID(String userID);

}

Any and all help is much appreciated. Thanks!

In BDProject you have property

private BDUser bdUser;

and in the repository you have:

public List<BDProject> findByUserID(String userID);

Error states that in BDProject you don't have property userID which is correct since you have bdUser.

Therefore, please change

findByUserID(String userID) to findByBdUserUserID(String userID)

You have created a BDProjectRepository interface for BDProject entity.
Please modify the method in that repository:

now: public List<BDProject> findByUserID(String userID);

should be: public List<BDProject> findByProID(String proID);

If you want to get BDProject for a specific user you can retrieve it by querying the related object as

public List<BDProject> findByBdUser_UserID(String proID);

When querying by fields in referenced object you should write it like ChildObject_ChildID

public interface BDProjectRepository extends CrudRepository<BDProject, String>
{
    public List<BDProject> findByBdUser_UserID(String userID);
}