BAEL-4887: fetching multiple entities in JPA query (#10803)

2021-05-25 21:48:22 +02:00
parent c24379b927
commit 27c53fd6de
6 changed files with 240 additions and 0 deletions
@@ -0,0 +1,84 @@
+package com.baeldung.jpa.returnmultipleentities;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+public class ReturnMultipleEntitiesIntegrationTest {
+    private static EntityManagerFactory factory;
+    private static EntityManager entityManager;
+    private ReportRepository reportRepository;
+
+    @Before
+    public void setup() {
+        factory = Persistence.createEntityManagerFactory("jpa-h2-return-multiple-entities");
+        entityManager = factory.createEntityManager();
+        reportRepository = new ReportRepository();
+        populateH2DB();
+    }
+
+    @Test
+    public void whenQueryingForMultipleEntitiesInOneQuery_thenJPAReturnsMultipleEntitiesInCorrectOrder() {
+        List<Object[]> reportDetails = reportRepository.find("user1@gmail.com");
+
+        assertEquals(2, reportDetails.size());
+
+        for (Object[] reportDetail : reportDetails) {
+            assertEquals(3, reportDetail.length);
+
+            Channel channel = (Channel) reportDetail[0];
+            Subscription subscription = (Subscription) reportDetail[1];
+            User user = (User) reportDetail[2];
+
+            assertEquals("single", subscription.getCode());
+            assertEquals("user1@gmail.com", user.getEmail());
+            if (!("eurosport".equals(channel.getCode()) || "hbo".equals(channel.getCode()))) {
+                fail();
+            }
+        }
+    }
+
+    private static void populateH2DB() {
+        entityManager.getTransaction().begin();
+
+        Subscription single = new Subscription();
+        single.setCode("single");
+
+        Subscription family = new Subscription();
+        family.setCode("family");
+
+        entityManager.persist(single);
+        entityManager.persist(family);
+
+        Channel bbc = new Channel();
+        bbc.setCode("bbc");
+        bbc.setSubscriptionId(family.getId());
+
+        Channel eurosport = new Channel();
+        eurosport.setCode("eurosport");
+        eurosport.setSubscriptionId(single.getId());
+
+        Channel hbo = new Channel();
+        hbo.setCode("hbo");
+        hbo.setSubscriptionId(single.getId());
+
+        entityManager.persist(bbc);
+        entityManager.persist(eurosport);
+        entityManager.persist(hbo);
+
+        User user1 = new User();
+        user1.setEmail("user1@gmail.com");
+        user1.setSubscriptionId(single.getId());
+
+        entityManager.persist(user1);
+
+        entityManager.getTransaction().commit();
+    }
+}