Spring Data JPA 中的动态@Query WHERE Cluase

Question

I'm using Spring Data JPA Repositories and would like to build custom WHERE clauses based on parameters passed through my method

Is it possible to set my WHERE clauses dynamically like so?

@Query("SELECT U FROM USERS U WHERE U.:columnName = :searchString)
List<User> findUserInfo(
@Param("columnName") String columnName,
@Param("searchString") String searchString);

So I could call my method like this:

findUserInfo("company", "Amazon")  

and it would create the query:

SELECT U FROM USERS U WHERE U.company = 'Amazon'

and:

findUserInfo("address", "123 Billy Graham Drive",)  

would create the query:

SELECT U FROM USERS U WHERE U.address = '123 Billy Graham Drive'

Answer 1

No, it is not possible. JPA will validate the queries, and it cannot validate a WHERE condition where it cannot know the column name (or attribute name). So, you cannot. If you want do to something like that you should use Criteria, or Specification which is part of Spring Data JPA. This will allow you to create such dynamic queries but programmatically and not as JPQL queries.

Answer 2

yes you can do this by using custom repository that extends QueryDslRepositorySupport

Please consider the below example

@Service 

Optional<User> findByEmail(String email);


@NoRepositoryBean
public interface UserRepositoryCustom {
    Optional<User> findByEmail(String email);
}

@Repository
public class UserRepositoryImpl extends QuerydslRepositorySupport implements UserRepositoryCustom {
    public UserRepositoryImpl() {
        super(User.class);
    }

    @Override
    public Optional<User> findByEmail(String email) {
        JPAQuery<User> query = getQuerydsl()
                .createQuery()
                .from(QUser.user)
                .where(QUser.user.email.equalsIgnoreCase(email))
                .select(QUser.user);
        return query.fetch().stream().findFirst();
    }
}

thus you can easily pass parameters to your JPA query.