diff --git a/backend/db/models/models.py b/backend/db/models/models.py
index 951b4a48..666ff7dc 100644
--- a/backend/db/models/models.py
+++ b/backend/db/models/models.py
@@ -1,30 +1,88 @@
+from datetime import datetime
+
+from sqlalchemy import Column, ForeignKey, Table
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from db.extensions import db
-from domain.models.models import SubjectDataclass, TeacherDataclass
+
+
+class User(db.Model):
+    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    name: Mapped[str]
+    email: Mapped[str]
+
+
+class Admin(db.Model):
+    id: Mapped[int] = mapped_column(ForeignKey(User.id), primary_key=True)
+
+
+teachers_subjects = Table(
+    "teachers_subjects",
+    db.Model.metadata,
+    Column("teacher_id", ForeignKey("teacher.id"), primary_key=True),
+    Column("subject_id", ForeignKey("subject.id"), primary_key=True),
+)
+students_subjects = Table(
+    "students_subjects",
+    db.Model.metadata,
+    Column("student_id", ForeignKey("student.id"), primary_key=True),
+    Column("subject_id", ForeignKey("subject.id"), primary_key=True),
+)
+students_groups = Table(
+    "students_groups",
+    db.Model.metadata,
+    Column("student_id", ForeignKey("student.id"), primary_key=True),
+    Column("group_id", ForeignKey("group.id"), primary_key=True),
+)
 
 
 class Teacher(db.Model):
-    id: Mapped[int] = mapped_column(primary_key=True)
-    name: Mapped[str] = mapped_column()
-    subjects: Mapped[list["Subject"]] = relationship("Subject", back_populates="teacher")
+    id: Mapped[int] = mapped_column(ForeignKey(User.id), primary_key=True)
+    subjects: Mapped[list["Subject"]] = relationship(secondary=teachers_subjects, back_populates="teachers")
 
-    def to_domain_model(self) -> TeacherDataclass:
-        return TeacherDataclass(
-            id=self.id,
-            name=self.name
-        )
+
+class Student(db.Model):
+    id: Mapped[int] = mapped_column(ForeignKey(User.id), primary_key=True)
+    subjects: Mapped[list["Subject"]] = relationship(secondary=students_subjects, back_populates="students")
+    groups: Mapped[list["Group"]] = relationship(secondary=students_groups, back_populates="students")
+    submissions: Mapped[list["Submission"]] = relationship(back_populates="student")
 
 
 class Subject(db.Model):
-    id: Mapped[int] = mapped_column(primary_key=True)
-    name: Mapped[str] = mapped_column()
-    teacher_id: Mapped[int] = mapped_column(db.ForeignKey("teacher.id"))
-    teacher: Mapped["Teacher"] = relationship("Teacher", back_populates="subjects")
-
-    def to_domain_model(self):
-        return SubjectDataclass(
-            id=self.id,
-            name=self.name,
-            teacher_id=self.teacher_id
-        )
+    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    name: Mapped[str]
+    teachers: Mapped[list[Teacher]] = relationship(secondary=teachers_subjects, back_populates="subjects")
+    students: Mapped[list[Student]] = relationship(secondary=students_subjects, back_populates="subjects")
+    projects: Mapped[list["Project"]] = relationship(back_populates="subject")
+
+
+class Project(db.Model):
+    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    name: Mapped[str]
+    deadline: Mapped[datetime]
+    archived: Mapped[bool]
+    requirements: Mapped[str]
+    visible: Mapped[bool]
+    max_students: Mapped[int]
+    subject_id: Mapped[int] = mapped_column(ForeignKey(Subject.id))
+    subject: Mapped[Subject] = relationship(back_populates="projects")
+    groups: Mapped[list["Group"]] = relationship(back_populates="project")
+
+
+class Group(db.Model):
+    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    project_id: Mapped[int] = mapped_column(ForeignKey(Project.id))
+    project: Mapped[Project] = relationship(back_populates="groups")
+    students: Mapped[list[Student]] = relationship(secondary=students_groups, back_populates="groups")
+    submissions: Mapped[list["Submission"]] = relationship(back_populates="group")
+
+
+class Submission(db.Model):
+    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    date_time: Mapped[datetime]
+    group_id: Mapped[int] = mapped_column(ForeignKey(Group.id))
+    group: Mapped[Group] = relationship(back_populates="submissions")
+    student_id: Mapped[int] = mapped_column(ForeignKey(Student.id))
+    student: Mapped[Student] = relationship(back_populates="submissions")
+    state: Mapped[int]
+    message: Mapped[str]