diff --git a/src/main/java/core/basesyntax/dao/impl/CommentDaoImpl.java b/src/main/java/core/basesyntax/dao/impl/CommentDaoImpl.java
index 5176c951f..cb388cf17 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 +14,50 @@ public CommentDaoImpl(SessionFactory sessionFactory) {
 
     @Override
     public Comment create(Comment entity) {
-        return null;
+        Transaction transaction = null;
+        try (Session session = factory.openSession()) {
+            transaction = session.beginTransaction();
+            session.save(entity);
+            transaction.commit();
+            return entity;
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't insert Comment entity", e);
+        }
     }
 
     @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 entity by id", e);
+        }
     }
 
     @Override
     public List<Comment> getAll() {
-        return null;
+        try (Session session = factory.openSession()) {
+            return session.createQuery("from Comment", Comment.class).list();
+        } catch (Exception e) {
+            throw new RuntimeException("Can't get all Comment entities", e);
+        }
     }
 
     @Override
     public void remove(Comment entity) {
-
+        Transaction transaction = null;
+        try (Session session = factory.openSession()) {
+            transaction = session.beginTransaction();
+            session.delete(entity);
+            transaction.commit();
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't delete Comment entity", e);
+        }
     }
 }
diff --git a/src/main/java/core/basesyntax/dao/impl/MessageDaoImpl.java b/src/main/java/core/basesyntax/dao/impl/MessageDaoImpl.java
index 9b899fa95..f1b61b7a3 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 +14,50 @@ public MessageDaoImpl(SessionFactory sessionFactory) {
 
     @Override
     public Message create(Message entity) {
-        return null;
+        Transaction transaction = null;
+        try (Session session = factory.openSession()) {
+            transaction = session.beginTransaction();
+            session.save(entity);
+            transaction.commit();
+            return entity;
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't insert Message entity", e);
+        }
     }
 
     @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 entity by id", e);
+        }
     }
 
     @Override
     public List<Message> getAll() {
-        return null;
+        try (Session session = factory.openSession()) {
+            return session.createQuery("from Message", Message.class).list();
+        } catch (Exception e) {
+            throw new RuntimeException("Can't get all Message entities", e);
+        }
     }
 
     @Override
     public void remove(Message entity) {
-
+        Transaction transaction = null;
+        try (Session session = factory.openSession()) {
+            transaction = session.beginTransaction();
+            session.delete(entity);
+            transaction.commit();
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't delete Message entity", 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..ff1671a06 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 +14,50 @@ public UserDaoImpl(SessionFactory sessionFactory) {
 
     @Override
     public User create(User entity) {
-        return null;
+        Transaction transaction = null;
+        try (Session session = factory.openSession()) {
+            transaction = session.beginTransaction();
+            session.save(entity);
+            transaction.commit();
+            return entity;
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't insert User entity", e);
+        }
     }
 
     @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 entity by id", e);
+        }
     }
 
     @Override
     public List<User> getAll() {
-        return null;
+        try (Session session = factory.openSession()) {
+            return session.createQuery("from User", User.class).list();
+        } catch (Exception e) {
+            throw new RuntimeException("Can't get all User entities", e);
+        }
     }
 
     @Override
     public void remove(User entity) {
-
+        Transaction transaction = null;
+        try (Session session = factory.openSession()) {
+            transaction = session.beginTransaction();
+            session.delete(entity);
+            transaction.commit();
+        } catch (Exception e) {
+            if (transaction != null) {
+                transaction.rollback();
+            }
+            throw new RuntimeException("Can't delete User entity", e);
+        }
     }
 }
diff --git a/src/main/java/core/basesyntax/model/Comment.java b/src/main/java/core/basesyntax/model/Comment.java
index 9fba0c920..855ca6c80 100644
--- a/src/main/java/core/basesyntax/model/Comment.java
+++ b/src/main/java/core/basesyntax/model/Comment.java
@@ -1,15 +1,25 @@
 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 java.util.List;
 
+@Entity
 public class Comment {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
     private String content;
+
+    @ManyToMany
+    @JoinTable(name = "comment_smile",
+            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..469ec4e01 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.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.OneToOne;
+
+@Entity
 public class Message {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
     private String content;
+
+    @OneToOne(cascade = jakarta.persistence.CascadeType.ALL, orphanRemoval = true)
+    @JoinColumn(name = "message_details_id")
     private MessageDetails messageDetails;
 
     public Long getId() {
diff --git a/src/main/java/core/basesyntax/model/User.java b/src/main/java/core/basesyntax/model/User.java
index 0141eef00..fa8261a44 100644
--- a/src/main/java/core/basesyntax/model/User.java
+++ b/src/main/java/core/basesyntax/model/User.java
@@ -1,10 +1,22 @@
 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.OneToMany;
 import java.util.List;
 
+@Entity
 public class User {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
     private String username;
+
+    @OneToMany(cascade = jakarta.persistence.CascadeType.ALL, orphanRemoval = true)
+    @JoinColumn(name = "user_id")
     private List<Comment> comments;
 
     public Long getId() {