DATAJPA-287 - Count query execution now considers distinct flag of query.

If the implementation of a Specification sets the distinct flag, we now create a count query that is honoring the distinct flag as well.

src/main/java/org/springframework/data/jpa/repository/support/SimpleJpaRepository.java

@@ -456,7 +456,12 @@ public class SimpleJpaRepository<T, ID extends Serializable> implements JpaRepos
 		CriteriaQuery<Long> query = builder.createQuery(Long.class);
 
 		Root<T> root = applySpecificationToCriteria(spec, query);
-		query.select(builder.count(root));
+
+		if (query.isDistinct()) {
+			query.select(builder.countDistinct(root));
+		} else {
+			query.select(builder.count(root));
+		}
 
 		return em.createQuery(query);
 	}

src/test/java/org/springframework/data/jpa/domain/sample/Child.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jpa.domain.sample;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.ManyToMany;
+
+@Entity
+public class Child {
+
+	@Id
+	@GeneratedValue
+	Long id;
+
+	@ManyToMany(mappedBy = "children")
+	Set<Parent> parents = new HashSet<Parent>();
+
+	/**
+	 * @param parent
+	 */
+	public Child add(Parent parent) {
+
+		this.parents.add(parent);
+
+		if (!parent.children.contains(this)) {
+			parent.add(this);
+		}
+
+		return this;
+	}
+}

src/test/java/org/springframework/data/jpa/domain/sample/Parent.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jpa.domain.sample;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.ManyToMany;
+
+@Entity
+public class Parent {
+
+	@Id
+	@GeneratedValue
+	Long id;
+
+	static final long serialVersionUID = -89717120680485957L;
+
+	@ManyToMany(cascade = CascadeType.ALL)
+	Set<Child> children = new HashSet<Child>();
+
+	public Parent add(Child child) {
+
+		this.children.add(child);
+
+		if (!child.parents.contains(this)) {
+			child.add(this);
+		}
+
+		return this;
+	}
+}

src/test/java/org/springframework/data/jpa/repository/EclipseLinkParentRepositoryIntegrationTests.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jpa.repository;
+
+import org.springframework.test.context.ContextConfiguration;
+
+@ContextConfiguration("classpath:eclipselink.xml")
+public class EclipseLinkParentRepositoryIntegrationTests extends ParentRepositoryIntegrationTests {
+
+}

src/test/java/org/springframework/data/jpa/repository/OpenJpaParentRepositoryIntegrationTests.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jpa.repository;
+
+import org.junit.Ignore;
+import org.springframework.test.context.ContextConfiguration;
+
+@ContextConfiguration("classpath:openjpa.xml")
+public class OpenJpaParentRepositoryIntegrationTests extends ParentRepositoryIntegrationTests {
+
+	@Override
+	@Ignore
+	public void testWithJoin() throws Exception {
+
+	}
+}

src/test/java/org/springframework/data/jpa/repository/ParentRepositoryIntegrationTests.java

@@ -0,0 +1,108 @@
+/*
+ * Copyright 2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jpa.repository;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+
+import java.util.List;
+import java.util.Set;
+
+import javax.persistence.criteria.CriteriaBuilder;
+import javax.persistence.criteria.CriteriaQuery;
+import javax.persistence.criteria.Path;
+import javax.persistence.criteria.Predicate;
+import javax.persistence.criteria.Root;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.jpa.domain.Specification;
+import org.springframework.data.jpa.domain.sample.Child;
+import org.springframework.data.jpa.domain.sample.Parent;
+import org.springframework.data.jpa.repository.sample.ParentRepository;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.transaction.annotation.Transactional;
+
+@Transactional
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration("classpath:config/namespace-application-context.xml")
+public class ParentRepositoryIntegrationTests {
+
+	@Autowired
+	ParentRepository repository;
+
+	@Before
+	public void setUp() {
+
+		repository.save(new Parent().add(new Child()));
+		repository.save(new Parent().add(new Child()).add(new Child()));
+		repository.save(new Parent().add(new Child()));
+		repository.save(new Parent());
+		repository.flush();
+	}
+
+	@Test
+	public void testWithoutJoin() throws Exception {
+
+		Page<Parent> page = repository.findAll(new Specification<Parent>() {
+			public Predicate toPredicate(Root<Parent> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
+				Path<Set<Child>> childrenPath = root.get("children");
+				query.distinct(true);
+				return cb.isNotEmpty(childrenPath);
+			}
+		}, new PageRequest(0, 5, new Sort(Sort.Direction.ASC, "id")));
+
+		List<Parent> content = page.getContent();
+
+		assertThat(content.size(), is(3));
+		assertThat(page.getSize(), is(5));
+		assertThat(page.getNumber(), is(0));
+		assertThat(page.getTotalElements(), is(3L));
+		assertThat(page.getTotalPages(), is(1));
+	}
+
+	@Test
+	public void testWithJoin() throws Exception {
+		Page<Parent> page = repository.findAll(new Specification<Parent>() {
+			public Predicate toPredicate(Root<Parent> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
+				Path<Set<Child>> childrenPath = root.get("children");
+				root.join("children");
+				// we are interesting in distinct items, especially when join presents in query
+				query.distinct(true);
+				return cb.isNotEmpty(childrenPath);
+			}
+		}, new PageRequest(0, 5, new Sort(Sort.Direction.ASC, "id")));
+
+		List<Parent> content = page.getContent();
+
+		// according to the initial setup there should be
+		// 3 parents which children collection is not empty
+		assertThat(content.size(), is(3));
+		assertThat(page.getSize(), is(5));
+		assertThat(page.getNumber(), is(0));
+
+		// we get here wrong total elements number since
+		// count query doesn't take into account the distinct marker of query
+		assertThat(page.getTotalElements(), is(3L));
+		assertThat(page.getTotalPages(), is(1));
+	}
+}

src/test/java/org/springframework/data/jpa/repository/sample/ParentRepository.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jpa.repository.sample;
+
+import org.springframework.data.jpa.domain.sample.Parent;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
+
+public interface ParentRepository extends JpaRepository<Parent, Long>, JpaSpecificationExecutor<Parent> {
+}

src/test/resources/META-INF/persistence.xml

@@ -2,13 +2,15 @@
 <persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
 	<persistence-unit name="default">
 		<class>org.springframework.data.jpa.domain.AbstractPersistable</class>
-		<class>org.springframework.data.jpa.domain.sample.User</class>
-		<class>org.springframework.data.jpa.domain.sample.SpecialUser</class>
-		<class>org.springframework.data.jpa.domain.sample.Role</class>
-		<class>org.springframework.data.jpa.domain.sample.Account</class>
 		<class>org.springframework.data.jpa.domain.AbstractAuditable</class>
+		<class>org.springframework.data.jpa.domain.sample.Account</class>
 		<class>org.springframework.data.jpa.domain.sample.AuditableUser</class>
         <class>org.springframework.data.jpa.domain.sample.AuditableRole</class>
+		<class>org.springframework.data.jpa.domain.sample.Parent</class>
+		<class>org.springframework.data.jpa.domain.sample.Child</class>
+		<class>org.springframework.data.jpa.domain.sample.Role</class>
+		<class>org.springframework.data.jpa.domain.sample.SpecialUser</class>
+		<class>org.springframework.data.jpa.domain.sample.User</class>
 		<class>org.springframework.data.jpa.domain.sample.SampleEntity</class>
 		<class>org.springframework.data.jpa.domain.sample.SampleEntityPK</class>
 		<class>org.springframework.data.jpa.domain.sample.SampleWithIdClass</class>