FastAPI many to many Response Schema and Relationship - sqlalchemy

Question

I am new to FastAPI and SQL-Alchemy, I am having trouble creating a schema and relationship of the many-to-many table (association table).
Here is an example, a student can enroll in multiple courses and a single course can have multiple students thus making many-to-many relationship.
Database Models
class Student(Base):
__tablename__ = "student"
id = Column(Integer, primary_key=True, index=True)
name = Column(String, nullable=False)
class Course(Base):
__tablename__ = "course"
id = Column(Integer, primary_key=True, index=True)
name = Column(String, nullable=False)
class StudentCourse(Base):
__tablename__ = "student_course"
id = Column(Integer, primary_key=True, index=True)
student_id = Column(Integer, ForeignKey("student.id"), nullable=False)
course_id = Column(Integer, ForeignKey("course.id"), nullable=False)
What relation do I need to define and how to design a schema from which I can get the following responses:
Response 1
[
{
"id": 1,
"name": "Student A",
"courses": [
{
"id": 1,
"name": "Course A"
},
{
"id": 2,
"name": "Course B"
}
]
},
{
"id": 2,
"name": "Student B",
"courses": [
{
"id": 1,
"name": "Course A"
},
{
"id": 3,
"name": "Course C"
}
]
},
{...}
]
Response 2
[
{
"id": 1,
"name": "Course A",
"students": [
{
"id": 1,
"name": "Student A"
},
{
"id": 2,
"name": "Student B"
}
]
},
{
"id": 2,
"name": "Course B",
"students": [
{
"id": 1,
"name": "Student A"
},
]
},
{
"id": 3,
"name": "Course C",
"students": [
{
"id": 2,
"name": "Student B"
},
]
},
{...}
]

Answer 1

In my opinion, it is simpler and preferable to use an association table instead of an association object for this many-to-many relationship, since you don't need extra fields.
So, according to the documentation, your database models should be:
student_course = Table("student_course", Base.metadata,
Column("student_id", ForeignKey("student.id"), primary_key=True),
Column("course_id", ForeignKey("course.id"), primary_key=True))
class Student(Base):
__tablename__ = "student"
id = Column(Integer, primary_key=True)
name = Column(String, nullable=False)
courses = relationship("Course",
secondary=student_course,
back_populates="students")
class Course(Base):
__tablename__ = "course"
id = Column(Integer, primary_key=True)
name = Column(String, nullable=False)
students = relationship("Student",
secondary=student_course,
back_populates="courses")
and your pydantic models (schemas):
class Student(BaseModel):
id: int
name: str
class Config:
orm_mode = True
class Course(BaseModel):
id: int
name: str
class Config:
orm_mode = True
class StudentOut(Student):
courses: List[Course]
class CourseOut(Course):
students: List[Student]
where StudentOut and CourseOut are your response models