Samples for the Intro to QueryDSL article, merged with existing querydsl module. Updated module dependencies. (#476)

querydsl/src/test/java/org/baeldung/querydsl/intro/QueryDSLTest.java

@@ -0,0 +1,215 @@
+/*
+ * (c) Центр ИТ, 2016. Все права защищены.
+ */
+package org.baeldung.querydsl.intro;
+
+import java.util.List;
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+
+import org.baeldung.querydsl.intro.entities.BlogPost;
+import org.baeldung.querydsl.intro.entities.QBlogPost;
+import org.baeldung.querydsl.intro.entities.QUser;
+import org.baeldung.querydsl.intro.entities.User;
+import com.querydsl.core.Tuple;
+import com.querydsl.core.types.dsl.Expressions;
+import com.querydsl.core.types.dsl.NumberPath;
+import com.querydsl.jpa.JPAExpressions;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+import org.junit.*;
+
+import static org.junit.Assert.*;
+
+public class QueryDSLTest {
+
+    private static EntityManagerFactory emf;
+
+    private EntityManager em;
+
+    private JPAQueryFactory queryFactory;
+
+    @BeforeClass
+    public static void populateDatabase() {
+        emf = Persistence.createEntityManagerFactory("org.baeldung.querydsl.intro");
+        EntityManager em = emf.createEntityManager();
+
+        em.getTransaction().begin();
+        User user1 = new User();
+        user1.setLogin("David");
+        em.persist(user1);
+
+        User user2 = new User();
+        user2.setLogin("Ash");
+        em.persist(user2);
+
+        User user3 = new User();
+        user3.setLogin("Call");
+        em.persist(user3);
+
+        User user4 = new User();
+        user4.setLogin("Bishop");
+        em.persist(user4);
+
+        BlogPost blogPost1 = new BlogPost();
+        blogPost1.setTitle("Hello World!");
+        blogPost1.setUser(user1);
+        em.persist(blogPost1);
+
+        BlogPost blogPost2 = new BlogPost();
+        blogPost2.setTitle("My Second Post");
+        blogPost2.setUser(user1);
+        em.persist(blogPost2);
+
+        BlogPost blogPost3 = new BlogPost();
+        blogPost3.setTitle("Hello World!");
+        blogPost3.setUser(user3);
+        em.persist(blogPost3);
+
+        em.getTransaction().commit();
+
+        em.close();
+
+    }
+
+    @Before
+    public void setUp() {
+        em = emf.createEntityManager();
+        em.getTransaction().begin();
+        queryFactory = new JPAQueryFactory(em);
+    }
+
+    @Test
+    public void whenFindByLogin_thenShouldReturnUser() {
+
+        QUser user = QUser.user;
+        User aUser = queryFactory.selectFrom(user)
+                .where(user.login.eq("David"))
+                .fetchOne();
+
+        assertNotNull(aUser);
+        assertEquals(aUser.getLogin(), "David");
+
+    }
+
+    @Test
+    public void whenUsingOrderBy_thenResultsShouldBeOrdered() {
+
+        QUser user = QUser.user;
+        List<User> users = queryFactory.selectFrom(user)
+                .orderBy(user.login.asc())
+                .fetch();
+
+        assertEquals(users.size(), 4);
+        assertEquals(users.get(0).getLogin(), "Ash");
+        assertEquals(users.get(1).getLogin(), "Bishop");
+        assertEquals(users.get(2).getLogin(), "Call");
+        assertEquals(users.get(3).getLogin(), "David");
+
+    }
+
+    @Test
+    public void whenGroupingByTitle_thenReturnsTuples() {
+
+        QBlogPost blogPost = QBlogPost.blogPost;
+
+        NumberPath<Long> count = Expressions.numberPath(Long.class, "c");
+
+        List<Tuple> userTitleCounts = queryFactory.select(blogPost.title, blogPost.id.count().as(count))
+                .from(blogPost)
+                .groupBy(blogPost.title)
+                .orderBy(count.desc())
+                .fetch();
+
+        assertEquals("Hello World!", userTitleCounts.get(0).get(blogPost.title));
+        assertEquals(new Long(2), userTitleCounts.get(0).get(count));
+
+        assertEquals("My Second Post", userTitleCounts.get(1).get(blogPost.title));
+        assertEquals(new Long(1), userTitleCounts.get(1).get(count));
+
+    }
+
+    @Test
+    public void whenJoiningWithCondition_thenResultCountShouldMatch() {
+
+        QUser user = QUser.user;
+        QBlogPost blogPost = QBlogPost.blogPost;
+
+        List<User> users = queryFactory.selectFrom(user)
+                .innerJoin(user.blogPosts, blogPost)
+                .on(blogPost.title.eq("Hello World!"))
+                .fetch();
+
+        assertEquals(2, users.size());
+    }
+
+    @Test
+    public void whenRefiningWithSubquery_thenResultCountShouldMatch() {
+
+        QUser user = QUser.user;
+        QBlogPost blogPost = QBlogPost.blogPost;
+
+        List<User> users = queryFactory.selectFrom(user)
+                .where(user.id.in(
+                        JPAExpressions.select(blogPost.user.id)
+                                .from(blogPost)
+                                .where(blogPost.title.eq("Hello World!"))))
+                .fetch();
+
+        assertEquals(2, users.size());
+    }
+
+    @Test
+    public void whenUpdating_thenTheRecordShouldChange() {
+
+        QUser user = QUser.user;
+
+        queryFactory.update(user)
+                .where(user.login.eq("Ash"))
+                .set(user.login, "Ash2")
+                .set(user.disabled, true)
+                .execute();
+
+        em.getTransaction().commit();
+
+        em.getTransaction().begin();
+
+        assertEquals(Boolean.TRUE,
+                queryFactory.select(user.disabled)
+                        .from(user)
+                        .where(user.login.eq("Ash2"))
+                        .fetchOne());
+
+    }
+
+    @Test
+    public void whenDeleting_thenTheRecordShouldBeAbsent() {
+
+        QUser user = QUser.user;
+
+        queryFactory.delete(user)
+                .where(user.login.eq("Bishop"))
+                .execute();
+
+        em.getTransaction().commit();
+
+        em.getTransaction().begin();
+
+        assertNull(queryFactory.selectFrom(user)
+                .where(user.login.eq("Bishop"))
+                .fetchOne());
+
+    }
+
+    @After
+    public void tearDown() {
+        em.getTransaction().commit();
+        em.close();
+    }
+
+    @AfterClass
+    public static void afterClass() {
+        emf.close();
+    }
+
+}