jpashop : 컬렉션 조회 v4 (jpa - dto 직접조회)

jpashop/src/main/java/com/example/jpashop/api/OrderApiController.java

@@ -4,6 +4,8 @@ import com.example.jpashop.domain.Order;
 import com.example.jpashop.domain.OrderItem;
 import com.example.jpashop.repository.OrderRepository;
 import com.example.jpashop.repository.OrderSearch;
+import com.example.jpashop.repository.order.query.OrderQueryDto;
+import com.example.jpashop.repository.order.query.OrderQueryRepository;
 import lombok.RequiredArgsConstructor;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestParam;
@@ -17,6 +19,7 @@ import java.util.stream.Collectors;
 public class OrderApiController {
 
     private final OrderRepository orderRepository;
+    private final OrderQueryRepository orderQueryRepository;
 
     @GetMapping("/api/v1/orders")
     public List<Order> ordersV1() {
@@ -55,4 +58,9 @@ public class OrderApiController {
                 .map(OrderDto::new)
                 .collect(Collectors.toList());
     }
+
+    @GetMapping("/api/v4/orders")
+    public List<OrderQueryDto> ordersV4() {
+        return orderQueryRepository.findOrderQueryDtos();
+    }
 }

jpashop/src/main/java/com/example/jpashop/repository/order/query/OrderItemQueryDto.java

@@ -0,0 +1,14 @@
+package com.example.jpashop.repository.order.query;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+
+@Data
+@AllArgsConstructor
+public class OrderItemQueryDto {
+
+    private Long orderId;
+    private String itemName;
+    private int orderPrice;
+    private int count;
+}

jpashop/src/main/java/com/example/jpashop/repository/order/query/OrderQueryDto.java

@@ -0,0 +1,28 @@
+package com.example.jpashop.repository.order.query;
+
+import com.example.jpashop.domain.Address;
+import com.example.jpashop.domain.OrderStatus;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+@Data
+public class OrderQueryDto {
+
+    private Long orderId;
+    private String name;
+    private LocalDateTime orderDate;
+    private OrderStatus orderStatus;
+    private Address address;
+    private List<OrderItemQueryDto> orderItems;
+
+    public OrderQueryDto(Long orderId, String name, LocalDateTime orderDate, OrderStatus orderStatus, Address address) {
+        this.orderId = orderId;
+        this.name = name;
+        this.orderDate = orderDate;
+        this.orderStatus = orderStatus;
+        this.address = address;
+    }
+}

jpashop/src/main/java/com/example/jpashop/repository/order/query/OrderQueryRepository.java

@@ -0,0 +1,43 @@
+package com.example.jpashop.repository.order.query;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Repository;
+
+import javax.persistence.EntityManager;
+import java.util.List;
+
+@Repository
+@RequiredArgsConstructor
+public class OrderQueryRepository {
+
+    private final EntityManager em;
+
+    public List<OrderQueryDto> findOrderQueryDtos() {
+        List<OrderQueryDto> result = findOrders();
+
+        result.forEach(o -> {
+            List<OrderItemQueryDto> orderItems = findOrderItems(o.getOrderId());
+            o.setOrderItems(orderItems);
+        });
+        return result;
+    }
+
+    private List<OrderItemQueryDto> findOrderItems(Long orderId) {
+        return em.createQuery(
+                "select new com.example.jpashop.repository.order.query.OrderItemQueryDto(oi.order.id, i.name, oi.orderPrice, oi.count)" +
+                        " from OrderItem oi" +
+                        " join oi.item i" +
+                        " where oi.order.id = :orderId", OrderItemQueryDto.class)
+                .setParameter("orderId", orderId)
+                .getResultList();
+    }
+
+    private List<OrderQueryDto> findOrders() {
+        return em.createQuery(
+                "select new com.example.jpashop.repository.order.query.OrderQueryDto(o.id, m.name, o.orderDate, o.status, d.address)" +
+                        " from Order o" +
+                        " join o.member m" +
+                        " join o.delivery d", OrderQueryDto.class)
+                .getResultList();
+    }
+}