crudrepository findBy method signature for list of

Question

I have an Entity Class like this:

@Entity
@Table(name = "CUSTOMER")
class Customer{
    @Id
    @Column(name = "Id")
    Long id;
    @Column(name = "EMAIL_ID")
    String emailId;
    @Column(name = "MOBILE")
    String mobile;
}

How to write findBy method for the below query using crudrepository spring data jpa?

select * from customer where (email, mobile) IN (("a@b.c","8971"), ("e@f.g", "8888"))

I'm expecting something like

List<Customer> findByEmailMobileIn(List<Tuple> tuples);

I want to get the list of customers from given pairs

Answer 1

I think this can be done with org.springframework.data.jpa.domain.Specification. You can pass a list of your tuples and proceed them this way (don't care that Tuple is not an entity, but you need to define this class):

public class CustomerSpecification implements Specification<Customer> {

    // names of the fields in your Customer entity
    private static final String CONST_EMAIL_ID = "emailId";
    private static final String CONST_MOBILE = "mobile";

    private List<MyTuple> tuples;

    public ClaimSpecification(List<MyTuple> tuples) {
        this.tuples = tuples;
    }

    @Override
    public Predicate toPredicate(Root<Customer> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
        // will be connected with logical OR
        List<Predicate> predicates = new ArrayList<>();

        tuples.forEach(tuple -> {
            List<Predicate> innerPredicates = new ArrayList<>();
            if (tuple.getEmail() != null) {
                 innerPredicates.add(cb.equal(root
                     .<String>get(CONST_EMAIL_ID), tuple.getEmail()));
            }
            if (tuple.getMobile() != null) {
                 innerPredicates.add(cb.equal(root
                     .<String>get(CONST_MOBILE), tuple.getMobile()));
            }
            // these predicates match a tuple, hence joined with AND
            predicates.add(andTogether(innerPredicates, cb));
        });

        return orTogether(predicates, cb);
    }

    private Predicate orTogether(List<Predicate> predicates, CriteriaBuilder cb) {
        return cb.or(predicates.toArray(new Predicate[0]));
    }

    private Predicate andTogether(List<Predicate> predicates, CriteriaBuilder cb) {
        return cb.and(predicates.toArray(new Predicate[0]));
    }
}

Your repo is supposed to extend interface JpaSpecificationExecutor<Customer>.

Then construct a specification with a list of tuples and pass it to the method customerRepo.findAll(Specification<Customer>) - it returns a list of customers.

Answer 2

It is maybe cleaner using a projection :

@Entity
@Table(name = "CUSTOMER")
class CustomerQueryData {
    @Id
    @Column(name = "Id")
    Long id;
    @OneToOne
    @JoinColumns(@JoinColumn(name = "emailId"), @JoinColumn(name = "mobile"))
    Contact contact;
}

The Contact Entity :

@Entity
@Table(name = "CUSTOMER")
class Contact{
    @Column(name = "EMAIL_ID")
    String emailId;
    @Column(name = "MOBILE")
    String mobile;
}

After specifying the entities, the repo :

CustomerJpaProjection extends Repository<CustomerQueryData, Long>, QueryDslPredicateExecutor<CustomerQueryData> {
    @Override
    List<CustomerQueryData> findAll(Predicate predicate);
 }

And the repo call :

ArrayList<Contact> contacts = new ArrayList<>();
contacts.add(new Contact("a@b.c","8971"));
contacts.add(new Contact("e@f.g", "8888"));
customerJpaProjection.findAll(QCustomerQueryData.customerQueryData.contact.in(contacts));

Not tested code.