diff --git a/src/main/java/core/basesyntax/dao/impl/CommentDaoImpl.java b/src/main/java/core/basesyntax/dao/impl/CommentDaoImpl.java
index 5176c951f..a3f753355 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 +14,63 @@ 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 create comment " + entity, e);
+        } finally {
+            if (session != null) {
+                session.close();
+            }
+        }
+
     }
 
     @Override
     public Comment get(Long id) {
-        return null;
+        try (Session session = factory.openSession()) {
+            return session.get(Comment.class, id);
+        } catch (Exception e) {
+            throw new RuntimeException("Can't get comment by id " + id, e);
+        }
     }
 
     @Override
     public List<Comment> getAll() {
-        return null;
+        try (Session session = factory.openSession()) {
+            return session.createQuery("SELECT c FROM Comment c", Comment.class).getResultList();
+        } catch (Exception e) {
+            throw new RuntimeException("Can't get all from comment table", e);
+        }
     }
 
     @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 " + entity, 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..b1bd079c6 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 +14,62 @@ 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 create message " + entity, e);
+        } finally {
+            if (session != null) {
+                session.close();
+            }
+        }
     }
 
     @Override
     public Message get(Long id) {
-        return null;
+        try (Session session = factory.openSession()) {
+            return session.get(Message.class, id);
+        } catch (Exception e) {
+            throw new RuntimeException("Can't get message by id " + id, e);
+        }
     }
 
     @Override
     public List<Message> getAll() {
-        return null;
+        try (Session session = factory.openSession()) {
+            return session.createQuery("SELECT m FROM Message m", Message.class).getResultList();
+        } catch (Exception e) {
+            throw new RuntimeException("Can't get all messages", e);
+        }
     }
 
     @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 " + entity, 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..872471c7d 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 +13,32 @@ 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 create message details " + entity, e);
+        } finally {
+            if (session != null) {
+                session.close();
+            }
+        }
     }
 
     @Override
     public MessageDetails get(Long id) {
-        return null;
+        try (Session session = factory.openSession()) {
+            return session.get(MessageDetails.class, id);
+        } catch (Exception e) {
+            throw new RuntimeException("Can't get message details by id " + id, e);
+        }
     }
 }
diff --git a/src/main/java/core/basesyntax/dao/impl/SmileDaoImpl.java b/src/main/java/core/basesyntax/dao/impl/SmileDaoImpl.java
index 559248cda..cc1496aff 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 +14,42 @@ 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 create smile " + entity, e);
+        } finally {
+            if (session != null) {
+                session.close();
+            }
+        }
+
     }
 
     @Override
     public Smile get(Long id) {
-        return null;
+        try (Session session = factory.openSession()) {
+            return session.get(Smile.class, id);
+        } catch (Exception e) {
+            throw new RuntimeException("Can't get smile by id " + id, e);
+        }
     }
 
     @Override
     public List<Smile> getAll() {
-        return null;
+        try (Session session = factory.openSession()) {
+            return session.createQuery("SELECT s FROM Smile s", Smile.class).getResultList();
+        } catch (Exception e) {
+            throw new RuntimeException("Can't get all smiles from DB", e);
+        }
     }
 }
diff --git a/src/main/java/core/basesyntax/dao/impl/UserDaoImpl.java b/src/main/java/core/basesyntax/dao/impl/UserDaoImpl.java
index 338d8248b..f2cd9fcaa 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 +14,64 @@ 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 create user " + entity, e);
+        } finally {
+            if (session != null) {
+                session.close();
+            }
+        }
     }
 
     @Override
     public User get(Long id) {
-        return null;
+        try (Session session = factory.openSession()) {
+            return session.get(User.class, id);
+        } catch (Exception e) {
+            throw new RuntimeException("Can't get user by id " + id, e);
+        }
     }
 
     @Override
     public List<User> getAll() {
-        return null;
+        try (Session session = factory.openSession()) {
+            return session.createQuery("SELECT u FROM User u", User.class).getResultList();
+        } catch (Exception e) {
+            throw new RuntimeException("Can't get all users", e);
+        }
     }
 
     @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 " + entity, 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..36b9d1f05 100644
--- a/src/main/java/core/basesyntax/model/Comment.java
+++ b/src/main/java/core/basesyntax/model/Comment.java
@@ -1,15 +1,20 @@
 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.OneToMany;
 import java.util.List;
 
+@Entity
 public class Comment {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
     private String content;
+    @OneToMany(cascade = CascadeType.DETACH)
     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..3f4d1340f 100644
--- a/src/main/java/core/basesyntax/model/Message.java
+++ b/src/main/java/core/basesyntax/model/Message.java
@@ -1,8 +1,19 @@
 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;
+
+@Entity
 public class Message {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
     private String content;
+    @OneToOne(cascade = {CascadeType.PERSIST, CascadeType.REMOVE})
     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..d988e46f0 100644
--- a/src/main/java/core/basesyntax/model/MessageDetails.java
+++ b/src/main/java/core/basesyntax/model/MessageDetails.java
@@ -1,8 +1,15 @@
 package core.basesyntax.model;
 
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
 import java.time.LocalDateTime;
 
+@Entity
 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/User.java b/src/main/java/core/basesyntax/model/User.java
index 0141eef00..482628413 100644
--- a/src/main/java/core/basesyntax/model/User.java
+++ b/src/main/java/core/basesyntax/model/User.java
@@ -1,10 +1,23 @@
 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.OneToMany;
 import java.util.List;
 
+@Entity
 public class User {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
     private String username;
+    @OneToMany(fetch = FetchType.EAGER, cascade = {CascadeType.PERSIST, CascadeType.MERGE})
+    @JoinColumn(name = "comments")
     private List<Comment> comments;
 
     public Long getId() {