diff --git a/persistence-modules/java-jpa/src/main/java/com/baeldung/jpa/projections/Product.java b/persistence-modules/java-jpa/src/main/java/com/baeldung/jpa/projections/Product.java new file mode 100644 index 0000000000..90f90be0c0 --- /dev/null +++ b/persistence-modules/java-jpa/src/main/java/com/baeldung/jpa/projections/Product.java @@ -0,0 +1,50 @@ +package com.baeldung.jpa.projections; + +import java.math.BigDecimal; + +import javax.persistence.Entity; +import javax.persistence.GeneratedValue; +import javax.persistence.GenerationType; +import javax.persistence.Id; + +@Entity +public class Product { + @Id + private long id; + private String name; + private String description; + private String category; + private BigDecimal unitPrice; + + public long getId() { + return id; + } + public void setId(long id) { + this.id = id; + } + public String getName() { + return name; + } + public void setName(String name) { + this.name = name; + } + public String getDescription() { + return description; + } + public void setDescription(String description) { + this.description = description; + } + public String getCategory() { + return category; + } + public void setCategory(String category) { + this.category = category; + } + public BigDecimal getUnitPrice() { + return unitPrice; + } + public void setUnitPrice(BigDecimal unitPrice) { + this.unitPrice = unitPrice; + } + +} diff --git a/persistence-modules/java-jpa/src/main/java/com/baeldung/jpa/projections/ProductRepository.java b/persistence-modules/java-jpa/src/main/java/com/baeldung/jpa/projections/ProductRepository.java new file mode 100644 index 0000000000..bb269e1de6 --- /dev/null +++ b/persistence-modules/java-jpa/src/main/java/com/baeldung/jpa/projections/ProductRepository.java @@ -0,0 +1,93 @@ +package com.baeldung.jpa.projections; + +import java.util.List; + +import javax.persistence.EntityManager; +import javax.persistence.EntityManagerFactory; +import javax.persistence.Persistence; +import javax.persistence.Query; +import javax.persistence.Tuple; +import javax.persistence.criteria.CriteriaBuilder; +import javax.persistence.criteria.CriteriaQuery; +import javax.persistence.criteria.Root; + +public class ProductRepository { + private EntityManager entityManager; + + public ProductRepository() { + EntityManagerFactory factory = Persistence.createEntityManagerFactory("jpa-projections"); + entityManager = factory.createEntityManager(); + } + + @SuppressWarnings("unchecked") + public List findAllNamesUsingJPQL() { + Query query = entityManager.createQuery("select name from Product"); + List resultList = query.getResultList(); + return resultList; + } + + @SuppressWarnings("unchecked") + public List findAllIdsUsingJPQL() { + Query query = entityManager.createQuery("select id from Product"); + List resultList = query.getResultList(); + return resultList; + } + + public List findAllNamesUsingCriteriaBuilder() { + CriteriaBuilder builder = entityManager.getCriteriaBuilder(); + CriteriaQuery query = builder.createQuery(String.class); + Root product = query.from(Product.class); + query.select(product.get("name")); + List resultList = entityManager.createQuery(query).getResultList(); + return resultList; + } + + @SuppressWarnings("unchecked") + public List findAllIdAndNamesUsingJPQL() { + Query query = entityManager.createQuery("select id, name from Product"); + List resultList = query.getResultList(); + return resultList; + } + + public List findAllIdAndNamesUsingCriteriaBuilderArray() { + CriteriaBuilder builder = entityManager.getCriteriaBuilder(); + CriteriaQuery query = builder.createQuery(Object[].class); + Root product = query.from(Product.class); + query.select(builder.array(product.get("id"), product.get("name"))); + List resultList = entityManager.createQuery(query).getResultList(); + return resultList; + } + + public List findAllIdNameUnitPriceUsingCriteriaQueryMultiselect() { + CriteriaBuilder builder = entityManager.getCriteriaBuilder(); + CriteriaQuery query = builder.createQuery(Object[].class); + Root product = query.from(Product.class); + query.multiselect(product.get("id"), product.get("name"), product.get("unitPrice")); + List resultList = entityManager.createQuery(query).getResultList(); + return resultList; + } + + public List findAllIdAndNamesUsingCriteriaBuilderTuple() { + CriteriaBuilder builder = entityManager.getCriteriaBuilder(); + CriteriaQuery query = builder.createQuery(Tuple.class); + Root product = query.from(Product.class); + query.select(builder.tuple(product.get("id"), product.get("name"))); + List resultList = entityManager.createQuery(query).getResultList(); + return resultList; + } + + public List findCountByCategoryUsingJPQL() { + Query query = entityManager.createQuery("select p.category, count(p) from Product p group by p.category"); + return query.getResultList(); + } + + public List findCountByCategoryUsingCriteriaBuilder() { + CriteriaBuilder builder = entityManager.getCriteriaBuilder(); + CriteriaQuery query = builder.createQuery(Object[].class); + Root product = query.from(Product.class); + query.multiselect(product.get("category"), builder.count(product)); + query.groupBy(product.get("category")); + List resultList = entityManager.createQuery(query).getResultList(); + return resultList; + } +} diff --git a/persistence-modules/java-jpa/src/main/resources/META-INF/persistence.xml b/persistence-modules/java-jpa/src/main/resources/META-INF/persistence.xml index 9c5543bc3c..298397e39d 100644 --- a/persistence-modules/java-jpa/src/main/resources/META-INF/persistence.xml +++ b/persistence-modules/java-jpa/src/main/resources/META-INF/persistence.xml @@ -147,7 +147,7 @@ - + org.hibernate.jpa.HibernatePersistenceProvider com.baeldung.jpa.entity.Student @@ -163,4 +163,21 @@ + + + org.hibernate.jpa.HibernatePersistenceProvider + com.baeldung.jpa.projections.Product + true + + + + + + + + + + + + \ No newline at end of file diff --git a/persistence-modules/java-jpa/src/main/resources/products_jpa.sql b/persistence-modules/java-jpa/src/main/resources/products_jpa.sql new file mode 100644 index 0000000000..43bc294f56 --- /dev/null +++ b/persistence-modules/java-jpa/src/main/resources/products_jpa.sql @@ -0,0 +1,4 @@ +insert into product(id, name, description, category) values (1,'Product Name 1','This is Product 1', 'category1'); +insert into product(id, name, description, category) values (2,'Product Name 2','This is Product 2', 'category1'); +insert into product(id, name, description, category) values (3,'Product Name 3','This is Product 3', 'category2'); +insert into product(id, name, description, category) values (4,'Product Name 4','This is Product 4', 'category3'); diff --git a/persistence-modules/java-jpa/src/test/java/com/baeldung/jpa/projections/HibernateProjectionsIntegrationTest.java b/persistence-modules/java-jpa/src/test/java/com/baeldung/jpa/projections/HibernateProjectionsIntegrationTest.java new file mode 100644 index 0000000000..47cc7cbaec --- /dev/null +++ b/persistence-modules/java-jpa/src/test/java/com/baeldung/jpa/projections/HibernateProjectionsIntegrationTest.java @@ -0,0 +1,133 @@ +package com.baeldung.jpa.projections; + +import static org.junit.Assert.assertEquals; +import static org.junit.Assert.assertNotNull; + +import java.util.List; + +import org.hibernate.Criteria; +import org.hibernate.Session; +import org.hibernate.SessionFactory; +import org.hibernate.Transaction; +import org.hibernate.cfg.AvailableSettings; +import org.hibernate.cfg.Configuration; +import org.hibernate.criterion.Order; +import org.hibernate.criterion.Projections; +import org.junit.After; +import org.junit.Before; +import org.junit.BeforeClass; +import org.junit.Test; + +public class HibernateProjectionsIntegrationTest { + private static Session session; + private static SessionFactory sessionFactory; + private Transaction transaction; + + @BeforeClass + public static void init() { + Configuration configuration = getConfiguration(); + configuration.addAnnotatedClass(Product.class); + sessionFactory = configuration.buildSessionFactory(); + } + + @Before + public void before() { + session = sessionFactory.getCurrentSession(); + transaction = session.beginTransaction(); + } + + @After + public void after() { + if(transaction.isActive()) { + transaction.rollback(); + } + } + + private static Configuration getConfiguration() { + Configuration cfg = new Configuration(); + cfg.setProperty(AvailableSettings.DIALECT, + "org.hibernate.dialect.H2Dialect"); + cfg.setProperty(AvailableSettings.HBM2DDL_AUTO, "none"); + cfg.setProperty(AvailableSettings.DRIVER, "org.h2.Driver"); + cfg.setProperty(AvailableSettings.URL, + "jdbc:h2:mem:myexceptiondb2;DB_CLOSE_DELAY=-1;;INIT=RUNSCRIPT FROM 'src/test/resources/products.sql'"); + cfg.setProperty(AvailableSettings.USER, "sa"); + cfg.setProperty(AvailableSettings.PASS, ""); + cfg.setProperty(AvailableSettings.CURRENT_SESSION_CONTEXT_CLASS, "thread"); + return cfg; + } + + + @SuppressWarnings("deprecation") + @Test + public void givenProductData_whenIdAndNameProjectionUsingCriteria_thenListOfObjectArrayReturned() { + Criteria criteria = session.createCriteria(Product.class); + criteria = criteria.setProjection(Projections.projectionList() + .add(Projections.id()) + .add(Projections.property("name"))); + List resultList = criteria.list(); + + assertNotNull(resultList); + assertEquals(4, resultList.size()); + assertEquals(1L, resultList.get(0)[0]); + assertEquals("Product Name 1", resultList.get(0)[1]); + assertEquals(2L, resultList.get(1)[0]); + assertEquals("Product Name 2", resultList.get(1)[1]); + assertEquals(3L, resultList.get(2)[0]); + assertEquals("Product Name 3", resultList.get(2)[1]); + assertEquals(4L, resultList.get(3)[0]); + assertEquals("Product Name 4", resultList.get(3)[1]); + } + + + @Test + public void givenProductData_whenNameProjectionUsingCriteria_thenListOfStringReturned() { + Criteria criteria = session.createCriteria(Product.class); + criteria = criteria.setProjection(Projections.property("name")); + List resultList = criteria.list(); + + assertNotNull(resultList); + assertEquals(4, resultList.size()); + assertEquals("Product Name 1", resultList.get(0)); + assertEquals("Product Name 2", resultList.get(1)); + assertEquals("Product Name 3", resultList.get(2)); + assertEquals("Product Name 4", resultList.get(3)); + } + + @Test + public void givenProductData_whenCountByCategoryUsingCriteria_thenOK() { + Criteria criteria = session.createCriteria(Product.class); + criteria = criteria.setProjection(Projections.projectionList() + .add(Projections.groupProperty("category")) + .add(Projections.rowCount())); + List resultList = criteria.list(); + + assertNotNull(resultList); + assertEquals(3, resultList.size()); + assertEquals("category1", resultList.get(0)[0]); + assertEquals(2L, resultList.get(0)[1]); + assertEquals("category2", resultList.get(1)[0]); + assertEquals(1L, resultList.get(1)[1]); + assertEquals("category3", resultList.get(2)[0]); + assertEquals(1L, resultList.get(2)[1]); + } + + @Test + public void givenProductData_whenCountByCategoryWithAliasUsingCriteria_thenOK() { + Criteria criteria = session.createCriteria(Product.class); + criteria = criteria.setProjection(Projections.projectionList() + .add(Projections.groupProperty("category")) + .add(Projections.alias(Projections.rowCount(), "count"))); + criteria.addOrder(Order.asc("count")); + List resultList = criteria.list(); + + assertNotNull(resultList); + assertEquals(3, resultList.size()); + assertEquals("category2", resultList.get(0)[0]); + assertEquals(1L, resultList.get(0)[1]); + assertEquals("category3", resultList.get(1)[0]); + assertEquals(1L, resultList.get(1)[1]); + assertEquals("category1", resultList.get(2)[0]); + assertEquals(2L, resultList.get(2)[1]); + } +} diff --git a/persistence-modules/java-jpa/src/test/java/com/baeldung/jpa/projections/ProductRepositoryIntegrationTest.java b/persistence-modules/java-jpa/src/test/java/com/baeldung/jpa/projections/ProductRepositoryIntegrationTest.java new file mode 100644 index 0000000000..c9a05709e3 --- /dev/null +++ b/persistence-modules/java-jpa/src/test/java/com/baeldung/jpa/projections/ProductRepositoryIntegrationTest.java @@ -0,0 +1,105 @@ +package com.baeldung.jpa.projections; + +import static org.junit.Assert.assertEquals; +import static org.junit.Assert.assertNotNull; + +import java.io.IOException; +import java.util.List; + +import org.junit.BeforeClass; +import org.junit.Test; + + +public class ProductRepositoryIntegrationTest { + private static ProductRepository productRepository; + + @BeforeClass + public static void once() throws IOException { + productRepository = new ProductRepository(); + } + + @Test + public void givenProductData_whenIdAndNameProjectionUsingJPQL_thenListOfObjectArrayReturned() { + List resultList = productRepository.findAllIdAndNamesUsingJPQL(); + + assertNotNull(resultList); + assertEquals(4, resultList.size()); + assertEquals(1L, resultList.get(0)[0]); + assertEquals("Product Name 1", resultList.get(0)[1]); + assertEquals(2L, resultList.get(1)[0]); + assertEquals("Product Name 2", resultList.get(1)[1]); + assertEquals(3L, resultList.get(2)[0]); + assertEquals("Product Name 3", resultList.get(2)[1]); + assertEquals(4L, resultList.get(3)[0]); + assertEquals("Product Name 4", resultList.get(3)[1]); + } + + @Test + public void givenProductData_whenIdAndNameProjectionUsingCriteriaBuilder_thenListOfObjectArrayReturned() { + List resultList = productRepository.findAllIdAndNamesUsingCriteriaBuilderArray(); + + assertNotNull(resultList); + assertEquals(4, resultList.size()); + assertEquals(1L, resultList.get(0)[0]); + assertEquals("Product Name 1", resultList.get(0)[1]); + assertEquals(2L, resultList.get(1)[0]); + assertEquals("Product Name 2", resultList.get(1)[1]); + assertEquals(3L, resultList.get(2)[0]); + assertEquals("Product Name 3", resultList.get(2)[1]); + assertEquals(4L, resultList.get(3)[0]); + assertEquals("Product Name 4", resultList.get(3)[1]); + } + + @SuppressWarnings("rawtypes") + @Test + public void givenProductData_whenNameProjectionUsingJPQL_thenListOfStringReturned() { + List resultList = productRepository.findAllNamesUsingJPQL(); + + assertNotNull(resultList); + assertEquals(4, resultList.size()); + assertEquals("Product Name 1", resultList.get(0)); + assertEquals("Product Name 2", resultList.get(1)); + assertEquals("Product Name 3", resultList.get(2)); + assertEquals("Product Name 4", resultList.get(3)); + } + + @Test + public void givenProductData_whenNameProjectionUsingCriteriaBuilder_thenListOfStringReturned() { + List resultList = productRepository.findAllNamesUsingCriteriaBuilder(); + + assertNotNull(resultList); + assertEquals(4, resultList.size()); + assertEquals("Product Name 1", resultList.get(0)); + assertEquals("Product Name 2", resultList.get(1)); + assertEquals("Product Name 3", resultList.get(2)); + assertEquals("Product Name 4", resultList.get(3)); + } + + @Test + public void givenProductData_whenCountByCategoryUsingJPQL_thenOK() { + List resultList = productRepository.findCountByCategoryUsingJPQL(); + + assertNotNull(resultList); + assertEquals(3, resultList.size()); + assertEquals("category1", resultList.get(0)[0]); + assertEquals(2L, resultList.get(0)[1]); + assertEquals("category2", resultList.get(1)[0]); + assertEquals(1L, resultList.get(1)[1]); + assertEquals("category3", resultList.get(2)[0]); + assertEquals(1L, resultList.get(2)[1]); + } + + @Test + public void givenProductData_whenCountByCategoryUsingCriteriaBuider_thenOK() { + List resultList = productRepository.findCountByCategoryUsingCriteriaBuilder(); + + assertNotNull(resultList); + assertEquals(3, resultList.size()); + assertEquals("category1", resultList.get(0)[0]); + assertEquals(2L, resultList.get(0)[1]); + assertEquals("category2", resultList.get(1)[0]); + assertEquals(1L, resultList.get(1)[1]); + assertEquals("category3", resultList.get(2)[0]); + assertEquals(1L, resultList.get(2)[1]); + } +} diff --git a/persistence-modules/java-jpa/src/test/resources/products.sql b/persistence-modules/java-jpa/src/test/resources/products.sql new file mode 100644 index 0000000000..d38ea1b037 --- /dev/null +++ b/persistence-modules/java-jpa/src/test/resources/products.sql @@ -0,0 +1,5 @@ +create table Product (id bigint not null, category varchar(255), description varchar(255), name varchar(255), unitPrice decimal(19,2), primary key (id)); +insert into product(id, name, description, category) values (1,'Product Name 1','This is Product 1', 'category1'); +insert into product(id, name, description, category) values (2,'Product Name 2','This is Product 2', 'category1'); +insert into product(id, name, description, category) values (3,'Product Name 3','This is Product 3', 'category2'); +insert into product(id, name, description, category) values (4,'Product Name 4','This is Product 4', 'category3');