如何在自定义spring存储库中实现自定义方法？[副本]

Question

假设我想有一个方法，它是获得超级主要客户，它有id=0。

@Entity
public class Customer {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private long id;
    private String firstName;
    private String lastName;

    protected Customer() {}

    public Customer(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    @Override
    public String toString() {
        return String.format(
                "Customer[id=%d, firstName='%s', lastName='%s']",
                id, firstName, lastName);
    }

}

public interface CustomerCustom {

   Customer getVeryMainCustomer();

}

其中声明了方法GetVeryMainCustomer。

然后我的公开存储库界面变成以下内容：

public interface CustomerRepository extends CrudRepository<Customer, Long>, CustomerCustom {

    List<Customer> findByLastName(String lastName);
}

它扩展了CrudRepository和myCustomerCustom。

我写的

public class CustomerCustomImpl implements CustomerCustom {

   @Override
   public Customer getVeryMainCustomer() {
      return null;
   }


}

bot不知道，在实现中写什么。如何接触客户？

Answer 1

使用@query:

public interface CustomerRepository extends CrudRepository<Customer, Long> {

    List<Customer> findByLastName(String lastName);

    @Query("SELECT c FROM Customer c WHERE c.id = 0")
    Customer getVeryMainCustomer();
}

Spring-data将使用注释中的查询为您处理实现。