diff --git a/src/main/java/Entities/Appointment.java b/src/main/java/Entities/Appointment.java
index 9565383..4815c0d 100644
--- a/src/main/java/Entities/Appointment.java
+++ b/src/main/java/Entities/Appointment.java
@@ -7,16 +7,18 @@
 @Table(name="Appointment")
 public class Appointment {
     @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private int AppointmentID;
     @ManyToOne
-    @JoinColumn(name="PetOwnerID",referencedColumnName = "PetOwnerID")
+    @JoinColumn(name = "PetOwnerID", referencedColumnName = "PetOwnerID")
     private PetOwner PetOwnerID;
-
     @ManyToOne
-    @JoinColumn(name="VetID",referencedColumnName = "VetID")
+    @JoinColumn(name = "VetID", referencedColumnName = "VetID")
     private Veterinarian VetID;
     private DateTimeLiteralExpression.DateTime AppointmentDate;
-    private int PetID;
+    @ManyToOne
+    @JoinColumn(name = "PetID", referencedColumnName = "PetID")
+    private Pet PetID;
     public int getAppointmentID() {
         return AppointmentID;
     }
@@ -48,16 +50,10 @@ public DateTimeLiteralExpression.DateTime getAppointmentDate() {
     public void setAppointmentDate(DateTimeLiteralExpression.DateTime appointmentDate) {
         AppointmentDate = appointmentDate;
     }
-
-    public int getPetID() {
+    public Pet getPetID() {
         return PetID;
     }
-
-    public void setPetID(int petID) {
+    public void setPetID(Pet petID) {
         PetID = petID;
     }
-
-
-
-
 }
diff --git a/src/main/java/Entities/Pet.java b/src/main/java/Entities/Pet.java
new file mode 100644
index 0000000..49a8e39
--- /dev/null
+++ b/src/main/java/Entities/Pet.java
@@ -0,0 +1,52 @@
+package Entities;
+
+import jakarta.persistence.*;
+
+import java.util.List;
+
+@Entity
+@Table(name = "Pet")
+public class Pet {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private int PetID;
+    private String PetName;
+    private int Age;
+    @ManyToOne
+    @JoinColumn(name = "PetTypeID", referencedColumnName = "PetTypeID")
+    private PetType PetTypeID;
+    private String Description;
+    @OneToMany(mappedBy = "Appointments")
+    private List<Appointment> Appointments;
+
+    public int getPetID() {
+        return PetID;
+    }
+    public void setPetID(int petID) {
+        PetID = petID;
+    }
+    public String getPetName() {
+        return PetName;
+    }
+    public void setPetName(String petName) {
+        PetName = petName;
+    }
+    public int getAge() {
+        return Age;
+    }
+    public void setAge(int age) {
+        Age = age;
+    }
+    public PetType getPetTypeID() {
+        return PetTypeID;
+    }
+    public void setPetTypeID(PetType petTypeID) {
+        PetTypeID = petTypeID;
+    }
+    public String getDescription() {
+        return Description;
+    }
+    public void setDescription(String description) {
+        Description = description;
+    }
+}
diff --git a/src/main/java/Entities/PetOwner.java b/src/main/java/Entities/PetOwner.java
index 3537309..c19c09c 100644
--- a/src/main/java/Entities/PetOwner.java
+++ b/src/main/java/Entities/PetOwner.java
@@ -2,15 +2,21 @@
 
 import jakarta.persistence.*;
 
+import java.util.List;
+
 @Entity
 @Table(name = "PetOwner")
 public class PetOwner{
     @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private int PetOwnerID;
     @OneToOne(cascade = CascadeType.ALL)
     @JoinColumn(name = "UserID", referencedColumnName = "UserID")
-    private User UserID;
+    private User User;
     private int PetID;
-
-    private int VetID;
+    @ManyToOne
+    @JoinColumn(name = "VetID", referencedColumnName = "VetID")
+    private Veterinarian Vet;
+    @OneToMany(mappedBy = "Appointment")
+    private List<Appointment> Appointments;
 }
diff --git a/src/main/java/Entities/User.java b/src/main/java/Entities/User.java
index 61c7a63..4b01784 100644
--- a/src/main/java/Entities/User.java
+++ b/src/main/java/Entities/User.java
@@ -6,6 +6,7 @@
 @Table(name = "User")
 public class User {
     @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private int UserID;
     private String Name;
     private String Surname;
@@ -14,9 +15,9 @@ public class User {
     @ManyToOne
     @JoinColumn(name = "UserTypeID", referencedColumnName = "UserTypeID")
     private UserType UserTypeID;
-    @OneToOne(mappedBy = "Veterinarian", cascade = CascadeType.ALL)
+    @OneToOne(mappedBy = "Veterinarian")
     private Veterinarian Vet;
-    @OneToOne(mappedBy = "PetOwner", cascade = CascadeType.ALL)
+    @OneToOne(mappedBy = "PetOwner")
     private PetOwner Owner;
 
     public int getUserID() {
@@ -25,9 +26,11 @@ public int getUserID() {
     public void setUserID(int userID) {
         UserID = userID;
     }
+
     public String getName() {
         return Name;
     }
+
     public void setName(String name) {
         Name = name;
     }
diff --git a/src/main/java/Entities/Veterinarian.java b/src/main/java/Entities/Veterinarian.java
index b224962..4d9b5d2 100644
--- a/src/main/java/Entities/Veterinarian.java
+++ b/src/main/java/Entities/Veterinarian.java
@@ -2,15 +2,19 @@
 
 import jakarta.persistence.*;
 
+import java.util.List;
+
 @Entity
 @Table(name = "Veterinarian")
 public class Veterinarian{
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private int VetID;
-    @OneToOne
-    private User UserID;
+    @OneToMany(mappedBy = "PetOwner")
+    private List<PetOwner> PetOwners;
     private String Clinic;
+    @OneToMany(mappedBy = "Appointment")
+    private List<Appointment> Appointments;
 
     public String getClinic() {
         return Clinic;
@@ -18,16 +22,16 @@ public String getClinic() {
     public void setClinic(String clinic) {
         Clinic = clinic;
     }
-    public User getUserID() {
-        return UserID;
-    }
-    public void setUserID(User userID) {
-        UserID = userID;
-    }
     public int getVetID() {
         return VetID;
     }
     public void setVetID(int vetID) {
         VetID = vetID;
     }
+    public List<PetOwner> getPetOwners() {
+        return PetOwners;
+    }
+    public void setPetOwners(List<PetOwner> petOwners) {
+        PetOwners = petOwners;
+    }
 }