From 59f3b02e877752d612a6cedde58456e940f5887e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?isa=20=C3=B6lmez?= Date: Tue, 9 Apr 2019 00:24:24 +0300 Subject: [PATCH] BAEL-2811: Added sample code for jpa joins (#6691) --- .../com/baeldung/joins/model/Department.java | 45 ++++++ .../com/baeldung/joins/model/Employee.java | 69 ++++++++++ .../java/com/baeldung/joins/model/Phone.java | 44 ++++++ .../resources/application-joins.properties | 1 + .../src/main/resources/db/import_joins.sql | 13 ++ .../joins/JpaJoinsIntegrationTest.java | 130 ++++++++++++++++++ 6 files changed, 302 insertions(+) create mode 100644 persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/joins/model/Department.java create mode 100644 persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/joins/model/Employee.java create mode 100644 persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/joins/model/Phone.java create mode 100644 persistence-modules/spring-data-jpa-2/src/main/resources/application-joins.properties create mode 100644 persistence-modules/spring-data-jpa-2/src/main/resources/db/import_joins.sql create mode 100644 persistence-modules/spring-data-jpa-2/src/test/java/com/baeldung/joins/JpaJoinsIntegrationTest.java diff --git a/persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/joins/model/Department.java b/persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/joins/model/Department.java new file mode 100644 index 0000000000..439f7532f5 --- /dev/null +++ b/persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/joins/model/Department.java @@ -0,0 +1,45 @@ +package com.baeldung.joins.model; + +import java.util.List; +import javax.persistence.Entity; +import javax.persistence.GeneratedValue; +import javax.persistence.GenerationType; +import javax.persistence.Id; +import javax.persistence.OneToMany; + +@Entity +public class Department { + + @Id + @GeneratedValue(strategy = GenerationType.AUTO) + private long id; + + private String name; + + @OneToMany(mappedBy = "department") + private List employees; + + 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 List getEmployees() { + return employees; + } + + public void setEmployees(List employees) { + this.employees = employees; + } +} diff --git a/persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/joins/model/Employee.java b/persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/joins/model/Employee.java new file mode 100644 index 0000000000..277274e61c --- /dev/null +++ b/persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/joins/model/Employee.java @@ -0,0 +1,69 @@ +package com.baeldung.joins.model; + +import java.util.List; +import javax.persistence.Entity; +import javax.persistence.GeneratedValue; +import javax.persistence.GenerationType; +import javax.persistence.Id; +import javax.persistence.ManyToOne; +import javax.persistence.OneToMany; +import javax.persistence.Table; + +@Entity +@Table(name = "joins_employee") +public class Employee { + + @Id + @GeneratedValue(strategy = GenerationType.IDENTITY) + private long id; + + private String name; + + private int age; + + @ManyToOne + private Department department; + + @OneToMany(mappedBy = "employee") + private List phones; + + 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 int getAge() { + return age; + } + + public void setAge(int age) { + this.age = age; + } + + public Department getDepartment() { + return department; + } + + public void setDepartment(Department department) { + this.department = department; + } + + public List getPhones() { + return phones; + } + + public void setPhones(List phones) { + this.phones = phones; + } +} diff --git a/persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/joins/model/Phone.java b/persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/joins/model/Phone.java new file mode 100644 index 0000000000..41382915b1 --- /dev/null +++ b/persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/joins/model/Phone.java @@ -0,0 +1,44 @@ +package com.baeldung.joins.model; + +import javax.persistence.Entity; +import javax.persistence.GeneratedValue; +import javax.persistence.GenerationType; +import javax.persistence.Id; +import javax.persistence.ManyToOne; + +@Entity +public class Phone { + + @Id + @GeneratedValue(strategy = GenerationType.IDENTITY) + private long id; + + private String number; + + @ManyToOne + private Employee employee; + + public long getId() { + return id; + } + + public void setId(long id) { + this.id = id; + } + + public String getNumber() { + return number; + } + + public void setNumber(String number) { + this.number = number; + } + + public Employee getEmployee() { + return employee; + } + + public void setEmployee(Employee employee) { + this.employee = employee; + } +} diff --git a/persistence-modules/spring-data-jpa-2/src/main/resources/application-joins.properties b/persistence-modules/spring-data-jpa-2/src/main/resources/application-joins.properties new file mode 100644 index 0000000000..fe2270293b --- /dev/null +++ b/persistence-modules/spring-data-jpa-2/src/main/resources/application-joins.properties @@ -0,0 +1 @@ +spring.datasource.data=classpath:db/import_joins.sql diff --git a/persistence-modules/spring-data-jpa-2/src/main/resources/db/import_joins.sql b/persistence-modules/spring-data-jpa-2/src/main/resources/db/import_joins.sql new file mode 100644 index 0000000000..e4772d6ff2 --- /dev/null +++ b/persistence-modules/spring-data-jpa-2/src/main/resources/db/import_joins.sql @@ -0,0 +1,13 @@ +INSERT INTO department (id, name) VALUES (1, 'Infra'); +INSERT INTO department (id, name) VALUES (2, 'Accounting'); +INSERT INTO department (id, name) VALUES (3, 'Management'); + +INSERT INTO joins_employee (id, name, age, department_id) VALUES (1, 'Baeldung', '35', 1); +INSERT INTO joins_employee (id, name, age, department_id) VALUES (2, 'John', '35', 2); +INSERT INTO joins_employee (id, name, age, department_id) VALUES (3, 'Jane', '35', 2); + +INSERT INTO phone (id, number, employee_id) VALUES (1, '111', 1); +INSERT INTO phone (id, number, employee_id) VALUES (2, '222', 1); +INSERT INTO phone (id, number, employee_id) VALUES (3, '333', 1); + +COMMIT; diff --git a/persistence-modules/spring-data-jpa-2/src/test/java/com/baeldung/joins/JpaJoinsIntegrationTest.java b/persistence-modules/spring-data-jpa-2/src/test/java/com/baeldung/joins/JpaJoinsIntegrationTest.java new file mode 100644 index 0000000000..d807da9845 --- /dev/null +++ b/persistence-modules/spring-data-jpa-2/src/test/java/com/baeldung/joins/JpaJoinsIntegrationTest.java @@ -0,0 +1,130 @@ +package com.baeldung.joins; + +import static org.assertj.core.api.Assertions.assertThat; + +import com.baeldung.joins.model.Department; +import com.baeldung.joins.model.Phone; +import java.util.List; +import javax.persistence.EntityManager; +import javax.persistence.PersistenceContext; +import javax.persistence.TypedQuery; +import org.junit.Test; +import org.junit.runner.RunWith; +import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest; +import org.springframework.test.context.ActiveProfiles; +import org.springframework.test.context.junit4.SpringRunner; + +@RunWith(SpringRunner.class) +@DataJpaTest +@ActiveProfiles("joins") +public class JpaJoinsIntegrationTest { + + @PersistenceContext + private EntityManager entityManager; + + @Test + public void whenPathExpressionIsUsedForSingleValuedAssociation_thenCreatesImplicitInnerJoin() { + TypedQuery query = entityManager.createQuery("SELECT e.department FROM Employee e", Department.class); + + List resultList = query.getResultList(); + + assertThat(resultList).hasSize(3); + assertThat(resultList).extracting("name") + .containsOnly("Infra", "Accounting", "Accounting"); + } + + @Test + public void whenJoinKeywordIsUsed_thenCreatesExplicitInnerJoin() { + TypedQuery query = entityManager.createQuery("SELECT d FROM Employee e JOIN e.department d", Department.class); + + List resultList = query.getResultList(); + + assertThat(resultList).hasSize(3); + assertThat(resultList).extracting("name") + .containsOnly("Infra", "Accounting", "Accounting"); + } + + @Test + public void whenInnerJoinKeywordIsUsed_thenCreatesExplicitInnerJoin() { + TypedQuery query = entityManager.createQuery("SELECT d FROM Employee e INNER JOIN e.department d", Department.class); + + List resultList = query.getResultList(); + + assertThat(resultList).hasSize(3); + assertThat(resultList).extracting("name") + .containsOnly("Infra", "Accounting", "Accounting"); + } + + @Test + public void whenEntitiesAreListedInFromAndMatchedInWhere_ThenCreatesJoin() { + TypedQuery query = entityManager.createQuery("SELECT d FROM Employee e, Department d WHERE e.department = d", Department.class); + + List resultList = query.getResultList(); + + assertThat(resultList).hasSize(3); + assertThat(resultList).extracting("name") + .containsOnly("Infra", "Accounting", "Accounting"); + } + + @Test + public void whenEntitiesAreListedInFrom_ThenCreatesCartesianProduct() { + TypedQuery query = entityManager.createQuery("SELECT d FROM Employee e, Department d", Department.class); + + List resultList = query.getResultList(); + + assertThat(resultList).hasSize(9); + assertThat(resultList).extracting("name") + .containsOnly("Infra", "Accounting", "Management", "Infra", "Accounting", "Management", "Infra", "Accounting", "Management"); + } + + @Test + public void whenCollectionValuedAssociationIsJoined_ThenCanSelect() { + TypedQuery query = entityManager.createQuery("SELECT ph FROM Employee e JOIN e.phones ph ", Phone.class); + + List resultList = query.getResultList(); + + assertThat(resultList).hasSize(3); + } + + @Test + public void whenMultipleEntitiesAreListedWithJoin_ThenCreatesMultipleJoins() { + TypedQuery query = entityManager.createQuery("SELECT ph FROM Employee e JOIN e.department d JOIN e.phones ph WHERE d.name IS NOT NULL", Phone.class); + + List resultList = query.getResultList(); + + assertThat(resultList).hasSize(3); + assertThat(resultList).extracting("number") + .containsOnly("111", "222", "333"); + } + + @Test + public void whenLeftKeywordIsSpecified_thenCreatesOuterJoinAndIncludesNonMatched() { + TypedQuery query = entityManager.createQuery("SELECT DISTINCT d FROM Department d LEFT JOIN d.employees e", Department.class); + + List resultList = query.getResultList(); + + assertThat(resultList).hasSize(3); + assertThat(resultList).extracting("name") + .containsOnly("Infra", "Accounting", "Management"); + } + + @Test + public void whenFetchKeywordIsSpecified_ThenCreatesFetchJoin() { + TypedQuery query = entityManager.createQuery("SELECT d FROM Department d JOIN FETCH d.employees", Department.class); + + List resultList = query.getResultList(); + + assertThat(resultList).hasSize(3); + assertThat(resultList).extracting("name") + .containsOnly("Infra", "Accounting", "Accounting"); + } + + @Test + public void whenLeftAndFetchKeywordsAreSpecified_ThenCreatesOuterFetchJoin() { + TypedQuery query = entityManager.createQuery("SELECT d FROM Department d LEFT JOIN FETCH d.employees", Department.class); + List resultList = query.getResultList(); + assertThat(resultList).hasSize(4); + assertThat(resultList).extracting("name") + .containsOnly("Infra", "Accounting", "Accounting", "Management"); + } +}