在JPA中使用WHERE查询实体

Question

I have this entity:

@Entity
@Table
public class Terminals implements Serializable {

    private static final long serialVersionUID = 5288308199642977991L;

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id", updatable = false, nullable = false)
    private Long id;

    @Column
    private int merchant_id;

    @Column
    private String terminalToken;

.....
}

I tried to use this query:

public Terminals getTerminalToken(String terminalToken) throws Exception {
        return entityManager.find(Terminals.class, terminalToken);
    }

Looks like it's selecting only the table key.

How I can select the table column terminalToken ?

Answer 1

You better use Spring data to build your queries along with JPA Repositories . You will just need to extend the JpaRepository interface, and follow the naming conventions to name your methods.

Your method will look like this:

public List<Terminal> findByTeminalToken(String TerminalToken);

Otherwise you will need to use entityManager.createQuery() method instead of entityManager.find() because the latter one is only used with the id column.

Answer 2

If you are looking for pure java (i am more in favour of Philipp solution) perhaps you wish to check out this solution. https://www.objectdb.com/java/jpa/query/criteria . Sorry for not posting a direct solution but i think it woths more to give you the source.

By the way, why not using spring data? Much easier