diff --git a/src/main/java/core/basesyntax/HibernateUtil.java b/src/main/java/core/basesyntax/HibernateUtil.java
index 06ceb9098..70099d741 100644
--- a/src/main/java/core/basesyntax/HibernateUtil.java
+++ b/src/main/java/core/basesyntax/HibernateUtil.java
@@ -4,7 +4,7 @@
 import org.hibernate.cfg.Configuration;
 
 public class HibernateUtil {
-    private static SessionFactory sessionFactory = initSessionFactory();
+    private static final SessionFactory sessionFactory = initSessionFactory();
 
     private HibernateUtil() {
     }
diff --git a/src/main/java/core/basesyntax/dao/impl/CommentDaoImpl.java b/src/main/java/core/basesyntax/dao/impl/CommentDaoImpl.java
index 5176c951f..2d79672c9 100644
--- a/src/main/java/core/basesyntax/dao/impl/CommentDaoImpl.java
+++ b/src/main/java/core/basesyntax/dao/impl/CommentDaoImpl.java
@@ -3,7 +3,9 @@
 import core.basesyntax.dao.CommentDao;
 import core.basesyntax.model.Comment;
 import java.util.List;
+import org.hibernate.Session;
 import org.hibernate.SessionFactory;
+import org.hibernate.Transaction;
 
 public class CommentDaoImpl extends AbstractDao implements CommentDao {
     public CommentDaoImpl(SessionFactory sessionFactory) {
@@ -12,21 +14,74 @@ public CommentDaoImpl(SessionFactory sessionFactory) {
 
     @Override
     public Comment create(Comment entity) {
-        return null;
+        Session session = null;
+        Transaction transaction = null;
+        try {
+            session = factory.openSession();
+            transaction = session.beginTransaction();
+
+            session.persist(entity);
+            transaction.commit();
+            return entity;
+
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't add Comment object in database", e);
+        } finally {
+            if (session != null) {
+                session.close();
+            }
+        }
     }
 
     @Override
     public Comment get(Long id) {
-        return null;
+        Comment comment = null;
+
+        try (Session session = factory.openSession()) {
+            comment = session.get(Comment.class, id);
+        } catch (Exception e) {
+            throw new RuntimeException("Can't retrieve Comment object by id:" + id, e);
+        }
+
+        return comment;
     }
 
     @Override
     public List<Comment> getAll() {
-        return null;
+        List<Comment> commentList = null;
+
+        try (Session session = factory.openSession()) {
+            commentList = session.createQuery("FROM Comment", Comment.class).list();
+        } catch (Exception e) {
+            throw new RuntimeException("Can't retrieve all Comment objects:", e);
+        }
+
+        return commentList;
     }
 
     @Override
     public void remove(Comment entity) {
+        Session session = null;
+        Transaction transaction = null;
+        try {
+            session = factory.openSession();
+            transaction = session.beginTransaction();
+
+            session.remove(entity);
 
+            transaction.commit();
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't remove Comment object from database", e);
+        } finally {
+            if (session != null) {
+                session.close();
+            }
+        }
     }
 }
diff --git a/src/main/java/core/basesyntax/dao/impl/MessageDaoImpl.java b/src/main/java/core/basesyntax/dao/impl/MessageDaoImpl.java
index 9b899fa95..e8640f26f 100644
--- a/src/main/java/core/basesyntax/dao/impl/MessageDaoImpl.java
+++ b/src/main/java/core/basesyntax/dao/impl/MessageDaoImpl.java
@@ -3,7 +3,9 @@
 import core.basesyntax.dao.MessageDao;
 import core.basesyntax.model.Message;
 import java.util.List;
+import org.hibernate.Session;
 import org.hibernate.SessionFactory;
+import org.hibernate.Transaction;
 
 public class MessageDaoImpl extends AbstractDao implements MessageDao {
     public MessageDaoImpl(SessionFactory sessionFactory) {
@@ -12,21 +14,74 @@ public MessageDaoImpl(SessionFactory sessionFactory) {
 
     @Override
     public Message create(Message entity) {
-        return null;
+        Session session = null;
+        Transaction transaction = null;
+        try {
+            session = factory.openSession();
+            transaction = session.beginTransaction();
+
+            session.persist(entity);
+            transaction.commit();
+            return entity;
+
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't add Message object in database", e);
+        } finally {
+            if (session != null) {
+                session.close();
+            }
+        }
     }
 
     @Override
     public Message get(Long id) {
-        return null;
+        Message message = null;
+
+        try (Session session = factory.openSession()) {
+            message = session.get(Message.class, id);
+        } catch (Exception e) {
+            throw new RuntimeException("Can't retrieve Message object by id:" + id, e);
+        }
+
+        return message;
     }
 
     @Override
     public List<Message> getAll() {
-        return null;
+        List<Message> messageList = null;
+
+        try (Session session = factory.openSession()) {
+            messageList = session.createQuery("FROM Message", Message.class).list();
+        } catch (Exception e) {
+            throw new RuntimeException("Can't retrieve all Comment objects:", e);
+        }
+
+        return messageList;
     }
 
     @Override
     public void remove(Message entity) {
+        Session session = null;
+        Transaction transaction = null;
+        try {
+            session = factory.openSession();
+            transaction = session.beginTransaction();
+
+            session.remove(entity);
 
+            transaction.commit();
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't remove Message object from database", e);
+        } finally {
+            if (session != null) {
+                session.close();
+            }
+        }
     }
 }
diff --git a/src/main/java/core/basesyntax/dao/impl/MessageDetailsDaoImpl.java b/src/main/java/core/basesyntax/dao/impl/MessageDetailsDaoImpl.java
index fb96d35aa..59974b2cf 100644
--- a/src/main/java/core/basesyntax/dao/impl/MessageDetailsDaoImpl.java
+++ b/src/main/java/core/basesyntax/dao/impl/MessageDetailsDaoImpl.java
@@ -2,7 +2,9 @@
 
 import core.basesyntax.dao.MessageDetailsDao;
 import core.basesyntax.model.MessageDetails;
+import org.hibernate.Session;
 import org.hibernate.SessionFactory;
+import org.hibernate.Transaction;
 
 public class MessageDetailsDaoImpl extends AbstractDao implements MessageDetailsDao {
     public MessageDetailsDaoImpl(SessionFactory sessionFactory) {
@@ -11,11 +13,37 @@ public MessageDetailsDaoImpl(SessionFactory sessionFactory) {
 
     @Override
     public MessageDetails create(MessageDetails entity) {
-        return null;
+        Session session = null;
+        Transaction transaction = null;
+        try {
+            session = factory.openSession();
+            transaction = session.beginTransaction();
+
+            session.persist(entity);
+            transaction.commit();
+            return entity;
+
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't add MessageDetails object in database", e);
+        } finally {
+            if (session != null) {
+                session.close();
+            }
+        }
     }
 
     @Override
     public MessageDetails get(Long id) {
-        return null;
+        MessageDetails messageDetails = null;
+
+        try (Session session = factory.openSession()) {
+            messageDetails = session.get(MessageDetails.class, id);
+        } catch (Exception e) {
+            throw new RuntimeException("Can't retrieve MessageDetails object by id:" + id, e);
+        }
+        return messageDetails;
     }
 }
diff --git a/src/main/java/core/basesyntax/dao/impl/SmileDaoImpl.java b/src/main/java/core/basesyntax/dao/impl/SmileDaoImpl.java
index 559248cda..5b9b6cbf7 100644
--- a/src/main/java/core/basesyntax/dao/impl/SmileDaoImpl.java
+++ b/src/main/java/core/basesyntax/dao/impl/SmileDaoImpl.java
@@ -3,7 +3,9 @@
 import core.basesyntax.dao.SmileDao;
 import core.basesyntax.model.Smile;
 import java.util.List;
+import org.hibernate.Session;
 import org.hibernate.SessionFactory;
+import org.hibernate.Transaction;
 
 public class SmileDaoImpl extends AbstractDao implements SmileDao {
     public SmileDaoImpl(SessionFactory sessionFactory) {
@@ -12,16 +14,51 @@ public SmileDaoImpl(SessionFactory sessionFactory) {
 
     @Override
     public Smile create(Smile entity) {
-        return null;
+        Session session = null;
+        Transaction transaction = null;
+        try {
+            session = factory.openSession();
+            transaction = session.beginTransaction();
+
+            session.persist(entity);
+            transaction.commit();
+            return entity;
+
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't add Smile object in database", e);
+        } finally {
+            if (session != null) {
+                session.close();
+            }
+        }
     }
 
     @Override
     public Smile get(Long id) {
-        return null;
+        Smile smile = null;
+
+        try (Session session = factory.openSession()) {
+            smile = session.get(Smile.class, id);
+        } catch (Exception e) {
+            throw new RuntimeException("Can't retrieve Smile object by id:" + id, e);
+        }
+
+        return smile;
     }
 
     @Override
     public List<Smile> getAll() {
-        return null;
+        List<Smile> smileList = null;
+
+        try (Session session = factory.openSession()) {
+            smileList = session.createQuery("FROM Smile", Smile.class).list();
+        } catch (Exception e) {
+            throw new RuntimeException("Can't retrieve all Smile objects:", e);
+        }
+
+        return smileList;
     }
 }
diff --git a/src/main/java/core/basesyntax/dao/impl/UserDaoImpl.java b/src/main/java/core/basesyntax/dao/impl/UserDaoImpl.java
index 338d8248b..02c5c5d75 100644
--- a/src/main/java/core/basesyntax/dao/impl/UserDaoImpl.java
+++ b/src/main/java/core/basesyntax/dao/impl/UserDaoImpl.java
@@ -3,7 +3,9 @@
 import core.basesyntax.dao.UserDao;
 import core.basesyntax.model.User;
 import java.util.List;
+import org.hibernate.Session;
 import org.hibernate.SessionFactory;
+import org.hibernate.Transaction;
 
 public class UserDaoImpl extends AbstractDao implements UserDao {
     public UserDaoImpl(SessionFactory sessionFactory) {
@@ -12,21 +14,74 @@ public UserDaoImpl(SessionFactory sessionFactory) {
 
     @Override
     public User create(User entity) {
-        return null;
+        Session session = null;
+        Transaction transaction = null;
+        try {
+            session = factory.openSession();
+            transaction = session.beginTransaction();
+
+            session.persist(entity);
+            transaction.commit();
+            return entity;
+
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't add User object in database", e);
+        } finally {
+            if (session != null) {
+                session.close();
+            }
+        }
     }
 
     @Override
     public User get(Long id) {
-        return null;
+        User user = null;
+
+        try (Session session = factory.openSession()) {
+            user = session.get(User.class, id);
+        } catch (Exception e) {
+            throw new RuntimeException("Can't retrieve User object by id:" + id, e);
+        }
+
+        return user;
     }
 
     @Override
     public List<User> getAll() {
-        return null;
+        List<User> userList = null;
+
+        try (Session session = factory.openSession()) {
+            userList = session.createQuery("FROM User", User.class).list();
+        } catch (Exception e) {
+            throw new RuntimeException("Can't retrieve all User objects:", e);
+        }
+
+        return userList;
     }
 
     @Override
     public void remove(User entity) {
+        Session session = null;
+        Transaction transaction = null;
+        try {
+            session = factory.openSession();
+            transaction = session.beginTransaction();
+
+            session.remove(entity);
 
+            transaction.commit();
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't remove User object from database", e);
+        } finally {
+            if (session != null) {
+                session.close();
+            }
+        }
     }
 }
diff --git a/src/main/java/core/basesyntax/model/Comment.java b/src/main/java/core/basesyntax/model/Comment.java
index 9fba0c920..c66861e38 100644
--- a/src/main/java/core/basesyntax/model/Comment.java
+++ b/src/main/java/core/basesyntax/model/Comment.java
@@ -1,15 +1,27 @@
 package core.basesyntax.model;
 
+import jakarta.persistence.Entity;
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.GenerationType;
 import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.JoinTable;
+import jakarta.persistence.ManyToMany;
+import jakarta.persistence.Table;
 import java.util.List;
 
+@Entity
+@Table(name = "comments")
 public class Comment {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
     private String content;
+
+    @ManyToMany
+    @JoinTable(name = "comments_smiles",
+            joinColumns = @JoinColumn(name = "comment_id"),
+            inverseJoinColumns = @JoinColumn(name = "smile_id"))
     private List<Smile> smiles;
 
     public Long getId() {
diff --git a/src/main/java/core/basesyntax/model/Message.java b/src/main/java/core/basesyntax/model/Message.java
index 672b5d485..0fd44e4e0 100644
--- a/src/main/java/core/basesyntax/model/Message.java
+++ b/src/main/java/core/basesyntax/model/Message.java
@@ -1,8 +1,21 @@
 package core.basesyntax.model;
 
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.OneToOne;
+import jakarta.persistence.Table;
+
+@Entity
+@Table(name = "messages")
 public class Message {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
     private String content;
+    @OneToOne(cascade = {CascadeType.REMOVE,CascadeType.PERSIST,CascadeType.MERGE})
     private MessageDetails messageDetails;
 
     public Long getId() {
diff --git a/src/main/java/core/basesyntax/model/MessageDetails.java b/src/main/java/core/basesyntax/model/MessageDetails.java
index 185023dd5..16e5a4ee7 100644
--- a/src/main/java/core/basesyntax/model/MessageDetails.java
+++ b/src/main/java/core/basesyntax/model/MessageDetails.java
@@ -1,8 +1,17 @@
 package core.basesyntax.model;
 
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
 import java.time.LocalDateTime;
 
+@Entity
+@Table(name = "messages_details")
 public class MessageDetails {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
     private String sender;
     private LocalDateTime sentTime;
diff --git a/src/main/java/core/basesyntax/model/Smile.java b/src/main/java/core/basesyntax/model/Smile.java
index 4395eb0f7..9218c0f8d 100644
--- a/src/main/java/core/basesyntax/model/Smile.java
+++ b/src/main/java/core/basesyntax/model/Smile.java
@@ -4,8 +4,10 @@
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.GenerationType;
 import jakarta.persistence.Id;
+import jakarta.persistence.Table;
 
 @Entity
+@Table(name = "smiles")
 public class Smile {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
diff --git a/src/main/java/core/basesyntax/model/User.java b/src/main/java/core/basesyntax/model/User.java
index 0141eef00..062a2afd3 100644
--- a/src/main/java/core/basesyntax/model/User.java
+++ b/src/main/java/core/basesyntax/model/User.java
@@ -1,10 +1,31 @@
 package core.basesyntax.model;
 
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.JoinTable;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
 import java.util.List;
 
+@Entity
+@Table(name = "users")
 public class User {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
+
     private String username;
+    @OneToMany(cascade = {CascadeType.PERSIST,CascadeType.MERGE},
+            fetch = FetchType.EAGER)
+    @JoinTable(name = "users_comments",
+            joinColumns = @JoinColumn(name = "user_id"),
+            inverseJoinColumns = @JoinColumn(name = "comment_id"))
+
     private List<Comment> comments;
 
     public Long getId() {