在我的情况下，如何使用枚举执行弹簧数据JPA查询？

Question

首先，这很长，但我想提供所有可能的信息。

我正在研究一个更大的查询，这将基于此基础，因此我没有采用更轻松或其他方法。此外，我无法真正改变我们实现DB和域对象的方式。

我的问题是我无法获得弹簧数据JPA查询来与枚举一起使用。该领域也是DB中的枚举。这是缩写的代码。

2个表的SQL：

CREATE TABLE my_order (
    id INT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
    creation_date TIMESTAMP NOT NULL,
);

CREATE TYPE ORDER_STATE as ENUM ('new', 'open', 'closed');
CREATE CAST (CHARACTER VARYING AS ORDER_STATE) WITH INOUT AS IMPLICIT;

CREATE TABLE my_order_history (
    id INT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
    order_date TIMESTAMP NOT NULL,
    order_state ORDER_STATE NOT NULL,
    order_id INT REFERENCES my_order
);

这是相应的域对象：

@Entity
@Table(name = "my_order")
public class Order {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;

    @Column(name = "creation_date")
    private Date creationDate;

    @OneToMany(mappedBy = "order", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    private List<OrderHistory> orderHistories;
}

@Entity
@Table(name = "my_order_history")
public class OrderHistory {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;

    @Column(name = "order_date ")
    private Date orderDate;

    @Column(name = "order_state")
    @Convert(converter = OrderStateConverter.class)
    private OrderState orderState

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "order_id", nullable = false)
    private Order order;
}

这是转换器：

@Component
@Converter(autoApply = true)
public class OrderStateConverter implement AttributeConverter<OrderState, String> {
   @Override
   public String convertToDatabaseColumn(OrderState attribute) {
       return attribute.getValue;
   }

   @Override
   public OrderState convertToEntityAttribute(String dbData) {
      return OrderState.fromValue(dbData);
   }
}

这是枚举：

public enum OrderState {
   NEW("new"), OPEN("open"), CLOSED("closed");

   @Getter
   private String value;

   private OrderState(String value) {
      this.value = value;
   }

   public static OrderState fromValue(String value) {
      for (OrderState orderState : values()) {
         if (orderState.getValue().equals(value)) {
             return orderState;
         }
      }
      return null;
   }
}

这是我的弹簧存储库。我将尝试的三种方法放在下面，然后在下面给您每个人都会收到的例外：

@Repository
public interface OrderRepository extends PagingAndSortingRepository<Order, Long> {
   @Query("SELECT o FROM Order o JOIN o.orderHistories oh WHERE oh.orderState = :orderState")
   List<Order> getOrdersByOrderState1(@Param("orderState") OrderState orderState);

   @Query("SELECT o FROM Order o JOIN o.orderHistories oh WHERE oh.orderState = :orderState")
   List<Order> getOrdersByOrderState2(@Param("orderState") String orderState);

   @Query("SELECT o FROM Order o JOIN o.orderHistories oh WHERE oh.orderState = :#(#orderState?.getValue())")
   List<Order> getOrdersByOrderState3(@Param("orderState") OrderState orderState);
}

对于＃1，当我提供一个阶层枚举时，我会得到以下例外：

Caused by: org.postgres.util.PSQLException: ERROR: operator does not exist: order_state = character varying
   Hint: No operator matches the given name and argument types. You might need explicit type casts.

对于＃2，当我提供Orderstate.getValue（）时，这是一个字符串，我会得到以下例外：

java.jang.IllegalArgumentException: Parameter value [new] did not match expected type [com.testing.enums.OrderState (n/a)]

对于＃3，当我提供一个阶梯枚举时，我会得到以下例外（与＃2相同）：

java.jang.IllegalArgumentException: Parameter value [new] did not match expected type [com.testing.enums.OrderState (n/a)]

基本上，我尝试发送枚举并获得错误，但我也得到了一个当我尝试发送字符串时，错误。有什么我能做的吗？到底发生了什么？