I am using spring-data-mongodb and querydsl-mongodb to perform more flexible queries.
My application has users and orders.
An user can have multiple orders, so my models looks like this:
public class User {
#Id
private String id;
private String username;
//getters and setters
}
public class Order {
#Id
private String id;
#DBRef
private User user;
//getters and setters
}
As you can see, there is an has-many relationship between users and orders.
Each order is assigned to an user, and the user is stored in #DBRef public User user attribute.
Now, lets say that an user has 10,000 orders.
How can i make the query to get all orders that belongs to an specific user ?
I have the OrderRepository:
public interface OrderRepository extends MongoRepository<Order, String>,
QueryDslPredicateExecutor<Order> {
}
I tried this solution but it doesnt return anything:
QOrder order = new QOrder("order");
Pageable pageable = new PageRequest(0, 100);
return userRepository.findAll(order.user.id.eq(anUserId), pageable);
I need to use querydsl because i want to build a service that can query orders by more many prameters than userid. For example i want to get all orders that belongs to user with specific username.
No need for QueryDSL when searching by ID. In OrderRepository, create an interface method:
public List<Order> findByUser(String userId);
Request example: curl http://localhost:8080/orders/search/findByUser?userId=5a950ea0a0deb42729b570c0
* I'm stuck on how to query orders, for example, of all users from certain city (some mongo join with user and address).
Related
I have the following User entity:
public class User extends PanacheEntityBase{
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "DataIdGenerator")
#Column(name = "id")
public Long id;
public String name;
public String location;
public int age;
}
I also have the following endpoint: '/user', with a 'select' query parameter where you provide the column names you want to receive. It should be possible to select any combination of columns like: /user?select=id,name, /user?select=id,age, /user?select=name,age, /user?select=age,name
Based on the 'select' query I want to use a projection to get the selected columns only. Currently I'm using the query to create the following query fe: /user?select=id,name to SELECT d.id, d.name FROM User d, however I need the DTO to be dynamic based on the columns provided too.
Currently I have the following projection where UserDTO is a class with id and name attributes. This works fine, but if I change any parameter I need a different DTO.
// This variable is dynamically created based on query parameters
String query = 'SELECT d.id, d.name FROM User d'
return User.find(query).project(UserDTO.class).list();
Is it possible to make this projection DTO class more dynamic, so it supports all combinations?
I suspect the Panache API is not flexible enough at the moment to do what you are asking.
But you could use the Hibernate Reactive API without Panache:
#Inject
Mutiny.SessionFactory sf;
public Uni<List<Tuple>> find(String query) {
return sf.withSession(session ->
session.createQuery(query, Tuple.class).getResultList()
);
}
Once you have the Tuple, you can convert it to the type you prefer.
#Entity
class Person{
private int id;
#OneToMany(mappedBy=owner)
private List<Pet> pets;
}
#Entity
class Pet{
private name;
private ZonedDateTime birthDate;
#ManyToOne
#JoinColumn(name="owner_id")
private Person owner;
}
I want to find all the persons and order them by their oldest pet birthday
The only way I can solve this is through #Formula , something like
#Entity
class Person{
private int id;
private List<Pet> pets;
#Formula("(SELECT p.birth_date FROM pet p WHERE p.owner_id = id order by p.birth_date ASC LIMIT 1)")
private ZonedDateTime oldestPetBirthday;
}
then
public List<Person> findPersonByOrderByOldestPetBirthdayAsc
But I don't want to touch raw sql, I am looking for something like
public List<Person> findPersonByOrderByPetsTop1OrderByBirthDateAsc
OR by using pageable something like:
PageRequest.of(page,pageSize,Sort.by(ASC, "pets.sort(BirthDateComparator).get(0)"))
is that possible?
Try to use #OrderBy annotation from #javax.persistence.OrderBy package on your one to many collection object.
#OrderBy("birthDate")
private List<Pet> pets;
Your solution with the formula is ok but suffers from some issues. Anyway, since you don't want to write SQL, you will have to use something like Blaze-Persistence Entity Views.
I created the library to allow easy mapping between JPA models and custom interface or abstract class defined models, something like Spring Data Projections on steroids. The idea is that you define your target structure(domain model) the way you like and map attributes(getters) via JPQL expressions to the entity model.
A DTO model for your use case could look like the following with Blaze-Persistence Entity-Views:
#EntityView(Person.class)
public interface PersonDto {
#IdMapping
Long getId();
#Limit(limit = "1", order = "birthDate desc)
#Mapping("pets")
OldestPetDto getOldestPet();
#EntityView(Pet.class)
interface OldestPetDto {
#IdMapping
Long getId();
ZonedDateTime getBirthDate();
}
}
Querying is a matter of applying the entity view to a query, the simplest being just a query by id.
PersonDto a = entityViewManager.find(entityManager, PersonDto.class, id);
The Spring Data integration allows you to use it almost like Spring Data Projections: https://persistence.blazebit.com/documentation/entity-view/manual/en_US/index.html#spring-data-features
Page<PersonDto> findAll(Pageable pageable);
The best part is, it will only fetch the state that is actually necessary!
Also, you can add a Sort for oldestPet.birthDate and it will work just like you would like it to!
Whats the best practise in Spring Boot to model custom relations between two entities in projection.
My entity Participation links to Competition, User and Team.
public class Participation
{
#Id
private String id;
#NonNull
#OneToOne
private Competition competition;
#OneToOne
private Team team;
#NonNull
#OneToOne
private User user;
private String info;
}
In my project, I want to link all participating Users for a specific Team to a Competition. To achieve this, I wrote a CompetitionDTO that has a field List<User> participants that is filled by a custom CompetitionService:
public Page<CompetitionDTO> teamParticipations (Team team, Pageable pageable)
{
Page<CompetitionDTO> page = cRep.findTeamParticipation(team, pageable);
page.forEach(competition -> competition.setParticipants(pRep.findParticipants(competition, team)));
return page;
}
I don't like this approach a lot because I assume there is a more elegant way to do this with Spring.
I saw the Selecting from Multiple Tables in Spring Data already had the solution for multiple tables.
I would like to know if it is possible to write custom query that has tables with pageable and sorting feature at the same time in Spring JPA/DATA.
SELECT s.service_id, s.name, us.rating_id
FROM services s,
ratings r,
user_services us
where
us.service_id = s.service_id and
us.rating_id = r.rating_id and
us.user_id= ?
;
Thanks for you help in advance.
Sorting feature is under question, but pagination is possible to use.
Assume that we have:
#Entity
public class Service {
#Id
private Long id;
private String name;
//...
}
#Entity
public class UserService {
#Id
private Long id;
#ManyToOne
User user;
#ManyToOne
Service service;
#ManyToOne
Rating rating;
//...
}
Then we create a projection:
public interface ServiceRating {
Long getServiceId();
String getServiceName();
Long getRatingId();
}
And then create a query method supported pagination:
public interface UserServiceRepo extends CrudRepository<UserService, Long> {
#Query("select s.id as serviceId, s.name as serviceName, us.rating.id as ratingId from UserService us join us.service s where us.user.id = ?1")
Page<ServiceRating> getServiceRating(Long userId, Pageable pageable);
}
(Since this query does not contain grouping it's not necessary to use an additional countQuery (see the parameter of #Query)).
Test:
Page<ServiceRating> pages = userServiceRepo.getServiceRating(1L, new PageRequest(0, 10));
assertThat(pages.getContent()).hasSize(10));
UPDATE
Sorting also working perfectly.
Just create a Sort object, specify direction and filed name (from the projection):
Sort sort = new Sort(Sort.Direction.ASC, "serviceName");
userServiceRepo.getServiceRating(1L, new PageRequest(0, 10, sort));
I'm currently using the spring-security libraries and I asked myself the following question: How should I combine my database model with the spring-security tables?
As you know spring-security needs two tables (users and authorities) to define an authentication manager in the database. From my pov there are now two possibilities where I store my additional user-information (like email, lastname, last-logged-on, ....)
I could have a plain user-table for authentication purposes and another one for the rest (linked by the username)
I extend the user-table of spring-security with my necessary attributes.
What is the best design from your perspective? What are your experiences?
Lomu
I created a POJO User which represents the User entity as conceived by the Spring Security library, and secondly I created a POJO ProfiledUser to represent a specialized type of user of my application. It is called ProfiledUser because I needed a user associated to a profile. Of course, a similar approach can be applyied for every type of user you need to represent. Basically, if you need more than one type of user you can make your classes to extend the User POJO.
In the following you find the class, with the JPA annotations.
#Entity
#Table(name="USERS")
#Inheritance(strategy=InheritanceType.JOINED)
public class User implements UserDetails {
private static final long serialVersionUID = 1L;
private long id;
private String username;
private String password;
private boolean enabled = true;
Set<Authority> authorities = new HashSet<Authority>();
//...getters & setters
}
#Entity
#Table(name="PROFILED_USERS")
public class ProfiledUser extends User{
private static final long serialVersionUID = 1L;
//some custom attributes
private PersonalData personalData;
private ContactData contactData;
private AddressData addressData;
//...getters & setters
}
If you need to represent only one type of user, I think it should work to add attributes to the User class. However, I prefer to separate the abstract concept of user defined by the Spring Security framework from my business logic. So I'd recommend to implement your own SomethingUser and extend the User class.
A person is a person and you should have a class/table representing a person†.
A user is a user, and is different from a person (hence the two different words), and you should have a class/table representing a user.
Can a person exist without a user? Yes
Can a user exist without a person? No, a username belongs to someone.
#Entity
abstract class Party {
#Id
Long id;
String name;
#OneToMany
List<User> usernames = new ArrayList<>();
}
#Entity
class Individual extends Party {
DateTime dateOfBirth;
}
#Entity
class User {
#ManyToOne
Party party;
String username;
String password; //you better use BCrypt/Blowfish hashing!
Boolean enabled = true;
}
You could instead use a #OneToOne relationship if you only want one username per party.
† Actually you should have a more abstract class/table representing a legal party.