Merge branch 'master' into bael-16656

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/Application.java

@@ -0,0 +1,12 @@
+package com.baeldung;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/batchinserts/DatasourceProxyBeanPostProcessor.java

@@ -0,0 +1,53 @@
+package com.baeldung.batchinserts;
+
+import java.lang.reflect.Method;
+import javax.sql.DataSource;
+import net.ttddyy.dsproxy.support.ProxyDataSourceBuilder;
+import org.aopalliance.intercept.MethodInterceptor;
+import org.aopalliance.intercept.MethodInvocation;
+import org.springframework.aop.framework.ProxyFactory;
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.context.annotation.Profile;
+import org.springframework.stereotype.Component;
+import org.springframework.util.ReflectionUtils;
+
+@Component
+@Profile("batchinserts")
+public class DatasourceProxyBeanPostProcessor implements BeanPostProcessor {
+
+    @Override
+    public Object postProcessBeforeInitialization(final Object bean, final String beanName) throws BeansException {
+        return bean;
+    }
+
+    @Override
+    public Object postProcessAfterInitialization(final Object bean, final String beanName) throws BeansException {
+        if (bean instanceof DataSource) {
+            ProxyFactory factory = new ProxyFactory(bean);
+            factory.setProxyTargetClass(true);
+            factory.addAdvice(new ProxyDataSourceInterceptor((DataSource) bean));
+            return factory.getProxy();
+        }
+
+        return bean;
+    }
+
+    private static class ProxyDataSourceInterceptor implements MethodInterceptor {
+
+        private final DataSource dataSource;
+
+        public ProxyDataSourceInterceptor(final DataSource dataSource) {
+            this.dataSource = ProxyDataSourceBuilder.create(dataSource).name("Batch-Insert-Logger").asJson().countQuery().logQueryToSysOut().build();
+        }
+
+        @Override
+        public Object invoke(final MethodInvocation invocation) throws Throwable {
+            Method proxyMethod = ReflectionUtils.findMethod(dataSource.getClass(), invocation.getMethod().getName());
+            if (proxyMethod != null) {
+                return proxyMethod.invoke(dataSource, invocation.getArguments());
+            }
+            return invocation.proceed();
+        }
+    }
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/batchinserts/model/School.java

@@ -0,0 +1,45 @@
+package com.baeldung.batchinserts.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 School {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.SEQUENCE)
+    private long id;
+
+    private String name;
+
+    @OneToMany(mappedBy = "school")
+    private List<Student> students;
+
+    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<Student> getStudents() {
+        return students;
+    }
+
+    public void setStudents(List<Student> students) {
+        this.students = students;
+    }
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/batchinserts/model/Student.java

@@ -0,0 +1,44 @@
+package com.baeldung.batchinserts.model;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.ManyToOne;
+
+@Entity
+public class Student {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.SEQUENCE)
+    private long id;
+
+    private String name;
+
+    @ManyToOne
+    private School school;
+
+    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 School getSchool() {
+        return school;
+    }
+
+    public void setSchool(School school) {
+        this.school = school;
+    }
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/boot/Application.java

@@ -0,0 +1,17 @@
+package com.baeldung.boot;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.domain.EntityScan;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+
+@SpringBootApplication
+@EnableJpaRepositories("com.baeldung")
+@EntityScan("com.baeldung")
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/boot/daos/impl/PersonInsertRepository.java

@@ -0,0 +1,31 @@
+package com.baeldung.boot.daos.impl;
+
+import org.springframework.stereotype.Repository;
+
+import com.baeldung.boot.domain.Person;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.transaction.Transactional;
+
+@Repository
+public class PersonInsertRepository {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Transactional
+    public void insertWithQuery(Person person) {
+        entityManager.createNativeQuery("INSERT INTO person (id, first_name, last_name) VALUES (?,?,?)")
+          .setParameter(1, person.getId())
+          .setParameter(2, person.getFirstName())
+          .setParameter(3, person.getLastName())
+          .executeUpdate();
+    }
+
+    @Transactional
+    public void insertWithEntityManager(Person person) {
+        this.entityManager.persist(person);
+    }
+
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/boot/daos/user/UserRepository.java

@@ -0,0 +1,99 @@
+package com.baeldung.boot.daos.user;
+
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import com.baeldung.boot.domain.User;
+
+import java.time.LocalDate;
+import java.util.Collection;
+import java.util.List;
+import java.util.stream.Stream;
+
+public interface UserRepository extends JpaRepository<User, Integer> , UserRepositoryCustom{
+
+    Stream<User> findAllByName(String name);
+
+    @Query("SELECT u FROM User u WHERE u.status = 1")
+    Collection<User> findAllActiveUsers();
+    
+    @Query("select u from User u where u.email like '%@gmail.com'")
+    List<User> findUsersWithGmailAddress();
+
+    @Query(value = "SELECT * FROM Users u WHERE u.status = 1", nativeQuery = true)
+    Collection<User> findAllActiveUsersNative();
+
+    @Query("SELECT u FROM User u WHERE u.status = ?1")
+    User findUserByStatus(Integer status);
+
+    @Query(value = "SELECT * FROM Users u WHERE u.status = ?1", nativeQuery = true)
+    User findUserByStatusNative(Integer status);
+
+    @Query("SELECT u FROM User u WHERE u.status = ?1 and u.name = ?2")
+    User findUserByStatusAndName(Integer status, String name);
+
+    @Query("SELECT u FROM User u WHERE u.status = :status and u.name = :name")
+    User findUserByStatusAndNameNamedParams(@Param("status") Integer status, @Param("name") String name);
+
+    @Query(value = "SELECT * FROM Users u WHERE u.status = :status AND u.name = :name", nativeQuery = true)
+    User findUserByStatusAndNameNamedParamsNative(@Param("status") Integer status, @Param("name") String name);
+
+    @Query("SELECT u FROM User u WHERE u.status = :status and u.name = :name")
+    User findUserByUserStatusAndUserName(@Param("status") Integer userStatus, @Param("name") String userName);
+
+    @Query("SELECT u FROM User u WHERE u.name like ?1%")
+    User findUserByNameLike(String name);
+
+    @Query("SELECT u FROM User u WHERE u.name like :name%")
+    User findUserByNameLikeNamedParam(@Param("name") String name);
+
+    @Query(value = "SELECT * FROM users u WHERE u.name LIKE ?1%", nativeQuery = true)
+    User findUserByNameLikeNative(String name);
+
+    @Query(value = "SELECT u FROM User u")
+    List<User> findAllUsers(Sort sort);
+
+    @Query(value = "SELECT u FROM User u ORDER BY id")
+    Page<User> findAllUsersWithPagination(Pageable pageable);
+
+    @Query(value = "SELECT * FROM Users ORDER BY id", countQuery = "SELECT count(*) FROM Users", nativeQuery = true)
+    Page<User> findAllUsersWithPaginationNative(Pageable pageable);
+
+    @Modifying
+    @Query("update User u set u.status = :status where u.name = :name")
+    int updateUserSetStatusForName(@Param("status") Integer status, @Param("name") String name);
+
+    @Modifying
+    @Query(value = "UPDATE Users u SET u.status = ? WHERE u.name = ?", nativeQuery = true)
+    int updateUserSetStatusForNameNative(Integer status, String name);
+
+    @Query(value = "INSERT INTO Users (name, age, email, status, active) VALUES (:name, :age, :email, :status, :active)", nativeQuery = true)
+    @Modifying
+    void insertUser(@Param("name") String name, @Param("age") Integer age, @Param("email") String email, @Param("status") Integer status, @Param("active") boolean active);
+    
+    @Modifying
+    @Query(value = "UPDATE Users u SET status = ? WHERE u.name = ?", nativeQuery = true)
+    int updateUserSetStatusForNameNativePostgres(Integer status, String name);
+    
+    @Query(value = "SELECT u FROM User u WHERE u.name IN :names")
+	  List<User> findUserByNameList(@Param("names") Collection<String> names);
+    
+    void deleteAllByCreationDateAfter(LocalDate date);
+
+    @Modifying(clearAutomatically = true, flushAutomatically = true)
+    @Query("update User u set u.active = false where u.lastLoginDate < :date")
+    void deactivateUsersNotLoggedInSince(@Param("date") LocalDate date);
+
+    @Modifying(clearAutomatically = true, flushAutomatically = true)
+    @Query("delete User u where u.active = false")
+    int deleteDeactivatedUsers();
+
+    @Modifying(clearAutomatically = true, flushAutomatically = true)
+    @Query(value = "alter table USERS add column deleted int(1) not null default 0", nativeQuery = true)
+    void addDeletedColumn();
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/boot/daos/user/UserRepositoryCustom.java

@@ -0,0 +1,14 @@
+package com.baeldung.boot.daos.user;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+import java.util.function.Predicate;
+
+import com.baeldung.boot.domain.User;
+
+public interface UserRepositoryCustom {
+    List<User> findUserByEmails(Set<String> emails);
+    
+    List<User> findAllUsersByPredicates(Collection<Predicate<User>> predicates);
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/boot/daos/user/UserRepositoryCustomImpl.java

@@ -0,0 +1,57 @@
+package com.baeldung.boot.daos.user;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+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 com.baeldung.boot.domain.User;
+
+public class UserRepositoryCustomImpl implements UserRepositoryCustom {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Override
+    public List<User> findUserByEmails(Set<String> emails) {
+        CriteriaBuilder cb = entityManager.getCriteriaBuilder();
+        CriteriaQuery<User> query = cb.createQuery(User.class);
+        Root<User> user = query.from(User.class);
+
+        Path<String> emailPath = user.get("email");
+
+        List<Predicate> predicates = new ArrayList<>();
+        for (String email : emails) {
+
+            predicates.add(cb.like(emailPath, email));
+
+        }
+        query.select(user)
+            .where(cb.or(predicates.toArray(new Predicate[predicates.size()])));
+
+        return entityManager.createQuery(query)
+            .getResultList();
+    }
+    
+    @Override
+    public List<User> findAllUsersByPredicates(Collection<java.util.function.Predicate<User>> predicates) {
+        List<User> allUsers = entityManager.createQuery("select u from User u", User.class).getResultList();
+        Stream<User> allUsersStream = allUsers.stream();
+        for (java.util.function.Predicate<User> predicate : predicates) {
+            allUsersStream = allUsersStream.filter(predicate);
+        }
+
+        return allUsersStream.collect(Collectors.toList());
+    }
+
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/boot/domain/Customer.java

@@ -0,0 +1,56 @@
+package com.baeldung.boot.domain;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+/**
+ * Customer Entity class
+ * @author ysharma2512
+ *
+ */
+@Entity
+public class Customer {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private Long id;
+    private String firstName;
+    private String lastName;
+
+    public Customer(String firstName, String lastName) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    @Override
+    public String toString() {
+        return String.format("Customer[id=%d, firstName='%s', lastName='%s']", id, firstName, lastName);
+    }
+
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/boot/domain/Person.java

@@ -0,0 +1,47 @@
+package com.baeldung.boot.domain;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Entity
+public class Person {
+
+    @Id
+    private Long id;
+    private String firstName;
+    private String lastName;
+
+    public Person() {
+    }
+
+    public Person(Long id, String firstName, String lastName) {
+        this.id = id;
+        this.firstName = firstName;
+        this.lastName = lastName;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/boot/domain/Possession.java

@@ -0,0 +1,83 @@
+package com.baeldung.boot.domain;
+
+import javax.persistence.*;
+import com.baeldung.boot.domain.Possession;
+
+@Entity
+@Table
+public class Possession {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    private String name;
+
+    public Possession() {
+        super();
+    }
+
+    public Possession(final String name) {
+        super();
+
+        this.name = name;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(final int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = (prime * result) + (int) (id ^ (id >>> 32));
+        result = (prime * result) + ((name == null) ? 0 : name.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null) {
+            return false;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        final Possession other = (Possession) obj;
+        if (id != other.id) {
+            return false;
+        }
+        if (name == null) {
+            if (other.name != null) {
+                return false;
+            }
+        } else if (!name.equals(other.name)) {
+            return false;
+        }
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("Possesion [id=").append(id).append(", name=").append(name).append("]");
+        return builder.toString();
+    }
+
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/boot/domain/User.java

@@ -0,0 +1,132 @@
+package com.baeldung.boot.domain;
+
+import javax.persistence.*;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.Objects;
+
+@Entity
+@Table(name = "users")
+public class User {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private int id;
+    private String name;
+    private LocalDate creationDate;
+    private LocalDate lastLoginDate;
+    private boolean active;
+    private int age;
+    @Column(unique = true, nullable = false)
+    private String email;
+    private Integer status;
+    @OneToMany
+    List<Possession> possessionList;
+
+    public User() {
+        super();
+    }
+
+    public User(String name,  LocalDate creationDate,String email, Integer status) {
+        this.name = name;
+        this.creationDate = creationDate;
+        this.email = email;
+        this.status = status;
+        this.active = true;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(final int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(final String email) {
+        this.email = email;
+    }
+
+    public Integer getStatus() {
+        return status;
+    }
+
+    public void setStatus(Integer status) {
+        this.status = status;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(final int age) {
+        this.age = age;
+    }
+    
+    public LocalDate getCreationDate() {
+        return creationDate;
+    }
+
+    public List<Possession> getPossessionList() {
+        return possessionList;
+    }
+
+    public void setPossessionList(List<Possession> possessionList) {
+        this.possessionList = possessionList;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("User [name=").append(name).append(", id=").append(id).append("]");
+        return builder.toString();
+    }
+    
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        User user = (User) o;
+        return id == user.id &&
+          age == user.age &&
+          Objects.equals(name, user.name) &&
+          Objects.equals(creationDate, user.creationDate) &&
+          Objects.equals(email, user.email) &&
+          Objects.equals(status, user.status);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, name, creationDate, age, email, status);
+    }
+
+    public LocalDate getLastLoginDate() {
+        return lastLoginDate;
+    }
+
+    public void setLastLoginDate(LocalDate lastLoginDate) {
+        this.lastLoginDate = lastLoginDate;
+    }
+
+    public boolean isActive() {
+        return active;
+    }
+
+    public void setActive(boolean active) {
+        this.active = active;
+    }
+
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/boot/passenger/CustomPassengerRepository.java

@@ -0,0 +1,8 @@
+package com.baeldung.boot.passenger;
+
+import java.util.List;
+
+interface CustomPassengerRepository {
+
+    List<Passenger> findOrderedBySeatNumberLimitedTo(int limit);
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/boot/passenger/Passenger.java

@@ -0,0 +1,82 @@
+package com.baeldung.boot.passenger;
+
+import javax.persistence.Basic;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import java.util.Objects;
+
+@Entity
+class Passenger {
+
+    @Id
+    @GeneratedValue
+    @Column(nullable = false)
+    private Long id;
+
+    @Basic(optional = false)
+    @Column(nullable = false)
+    private String firstName;
+
+    @Basic(optional = false)
+    @Column(nullable = false)
+    private String lastName;
+
+    @Basic(optional = false)
+    @Column(nullable = false)
+    private Integer seatNumber;
+
+    private Passenger(String firstName, String lastName, Integer seatNumber) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.seatNumber = seatNumber;
+    }
+
+    static Passenger from(String firstName, String lastName, Integer seatNumber) {
+        return new Passenger(firstName, lastName, seatNumber);
+    }
+
+    @Override
+    public boolean equals(Object object) {
+        if (this == object)
+            return true;
+        if (object == null || getClass() != object.getClass())
+            return false;
+        Passenger passenger = (Passenger) object;
+        return getSeatNumber() == passenger.getSeatNumber() && Objects.equals(getFirstName(), passenger.getFirstName())
+          && Objects.equals(getLastName(), passenger.getLastName());
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(getFirstName(), getLastName(), getSeatNumber());
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder toStringBuilder = new StringBuilder(getClass().getSimpleName());
+        toStringBuilder.append("{ id=").append(id);
+        toStringBuilder.append(", firstName='").append(firstName).append('\'');
+        toStringBuilder.append(", lastName='").append(lastName).append('\'');
+        toStringBuilder.append(", seatNumber=").append(seatNumber);
+        toStringBuilder.append('}');
+        return toStringBuilder.toString();
+    }
+
+    Long getId() {
+        return id;
+    }
+
+    String getFirstName() {
+        return firstName;
+    }
+
+    String getLastName() {
+        return lastName;
+    }
+
+    Integer getSeatNumber() {
+        return seatNumber;
+    }
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/boot/passenger/PassengerRepository.java

@@ -0,0 +1,22 @@
+package com.baeldung.boot.passenger;
+
+import java.util.List;
+
+import org.springframework.data.domain.Sort;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+interface PassengerRepository extends JpaRepository<Passenger, Long>, CustomPassengerRepository {
+
+    Passenger findFirstByOrderBySeatNumberAsc();
+
+    Passenger findTopByOrderBySeatNumberAsc();
+
+    List<Passenger> findByOrderBySeatNumberAsc();
+
+    List<Passenger> findByFirstNameIgnoreCase(String firstName);
+
+    List<Passenger> findByLastNameOrderBySeatNumberAsc(String lastName);
+
+    List<Passenger> findByLastName(String lastName, Sort sort);
+
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/boot/passenger/PassengerRepositoryImpl.java

@@ -0,0 +1,20 @@
+package com.baeldung.boot.passenger;
+
+import org.springframework.stereotype.Repository;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import java.util.List;
+
+@Repository
+class PassengerRepositoryImpl implements CustomPassengerRepository {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Override
+    public List<Passenger> findOrderedBySeatNumberLimitedTo(int limit) {
+        return entityManager.createQuery("SELECT p FROM Passenger p ORDER BY p.seatNumber",
+          Passenger.class).setMaxResults(limit).getResultList();
+    }
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/entity/Employee.java

@@ -0,0 +1,36 @@
+package com.baeldung.entity;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Entity
+public class Employee {
+
+    @Id
+    private Long id;
+    private String name;
+    
+    public Employee() {
+    }
+
+    public Employee(Long id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    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;
+    }
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/multipledb/MultipleDbApplication.java

@@ -0,0 +1,14 @@
+package com.baeldung.multipledb;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class MultipleDbApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(MultipleDbApplication.class, args);
+    }
+    
+}
+

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/multipledb/PersistenceProductConfiguration.java

@@ -0,0 +1,68 @@
+package com.baeldung.multipledb;
+
+import com.google.common.base.Preconditions;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.core.env.Environment;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.jdbc.datasource.DriverManagerDataSource;
+import org.springframework.orm.jpa.JpaTransactionManager;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
+import org.springframework.transaction.PlatformTransactionManager;
+
+import javax.sql.DataSource;
+import java.util.HashMap;
+
+@Configuration
+@PropertySource({"classpath:persistence-multiple-db.properties"})
+@EnableJpaRepositories(basePackages = "com.baeldung.multipledb.dao.product", entityManagerFactoryRef = "productEntityManager", transactionManagerRef = "productTransactionManager")
+@Profile("!tc")
+public class PersistenceProductConfiguration {
+    @Autowired
+    private Environment env;
+
+    public PersistenceProductConfiguration() {
+        super();
+    }
+
+    //
+
+    @Bean
+    public LocalContainerEntityManagerFactoryBean productEntityManager() {
+        final LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
+        em.setDataSource(productDataSource());
+        em.setPackagesToScan("com.baeldung.multipledb.model.product");
+
+        final HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
+        em.setJpaVendorAdapter(vendorAdapter);
+        final HashMap<String, Object> properties = new HashMap<String, Object>();
+        properties.put("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
+        properties.put("hibernate.dialect", env.getProperty("hibernate.dialect"));
+        em.setJpaPropertyMap(properties);
+
+        return em;
+    }
+
+    @Bean
+    public DataSource productDataSource() {
+        final DriverManagerDataSource dataSource = new DriverManagerDataSource();
+        dataSource.setDriverClassName(Preconditions.checkNotNull(env.getProperty("jdbc.driverClassName")));
+        dataSource.setUrl(Preconditions.checkNotNull(env.getProperty("product.jdbc.url")));
+        dataSource.setUsername(Preconditions.checkNotNull(env.getProperty("jdbc.user")));
+        dataSource.setPassword(Preconditions.checkNotNull(env.getProperty("jdbc.pass")));
+
+        return dataSource;
+    }
+
+    @Bean
+    public PlatformTransactionManager productTransactionManager() {
+        final JpaTransactionManager transactionManager = new JpaTransactionManager();
+        transactionManager.setEntityManagerFactory(productEntityManager().getObject());
+        return transactionManager;
+    }
+
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/multipledb/dao/product/ProductRepository.java

@@ -0,0 +1,13 @@
+package com.baeldung.multipledb.dao.product;
+
+import java.util.List;
+
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.repository.PagingAndSortingRepository;
+
+import com.baeldung.multipledb.model.product.ProductMultipleDB;
+
+public interface ProductRepository extends PagingAndSortingRepository<ProductMultipleDB, Integer> {
+
+    List<ProductMultipleDB> findAllByPrice(double price, Pageable pageable);
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/multipledb/model/product/ProductMultipleDB.java

@@ -0,0 +1,67 @@
+package com.baeldung.multipledb.model.product;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(schema = "products")
+public class ProductMultipleDB {
+
+    @Id
+    private int id;
+
+    private String name;
+
+    private double price;
+
+    public ProductMultipleDB() {
+        super();
+    }
+
+    private ProductMultipleDB(int id, String name, double price) {
+        super();
+        this.id = id;
+        this.name = name;
+        this.price = price;
+    }
+
+    public static ProductMultipleDB from(int id, String name, double price) {
+        return new ProductMultipleDB(id, name, price);
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(final int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    public double getPrice() {
+        return price;
+    }
+
+    public void setPrice(final double price) {
+        this.price = price;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("Product [name=")
+            .append(name)
+            .append(", id=")
+            .append(id)
+            .append("]");
+        return builder.toString();
+    }
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/repository/EmployeeRepository.java

@@ -0,0 +1,9 @@
+package com.baeldung.repository;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import com.baeldung.entity.Employee;
+
+public interface EmployeeRepository extends JpaRepository<Employee, Long> {
+
+}

persistence-modules/spring-data-jpa-3/src/main/java/com/baeldung/tx/Payment.java

@@ -0,0 +1,55 @@
+package com.baeldung.tx;
+
+import javax.persistence.*;
+
+@Entity
+public class Payment {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    private Long amount;
+
+    @Column(unique = true)
+    private String referenceNumber;
+
+    @Enumerated(EnumType.STRING)
+    private State state;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public Long getAmount() {
+        return amount;
+    }
+
+    public void setAmount(Long amount) {
+        this.amount = amount;
+    }
+
+    public String getReferenceNumber() {
+        return referenceNumber;
+    }
+
+    public void setReferenceNumber(String referenceNumber) {
+        this.referenceNumber = referenceNumber;
+    }
+
+    public State getState() {
+        return state;
+    }
+
+    public void setState(State state) {
+        this.state = state;
+    }
+
+    public enum State {
+        STARTED, FAILED, SUCCESSFUL
+    }
+}