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sqlalchemy.exc.InvalidRequestError: When initializing mapper mapped class Order->order, expression 'Status' failed to locate a name ('Status')

Cannot save record to my db.
I created endpoint which makes user and saves him to db:
#router.post("/user/register/", tags=['user'], status_code=201)
async def user_register_web(user: RegisterWebSchema, db: Session = Depends(get_db)):
if user.password != user.password_repeat:
raise HTTPException(status_code=404, detail="Passwords dont match each other!")
db_user = UserModel(name=user.name.title(), surname=user.surname.title(), email=user.email,
phone_number=user.phone_number, login=user.login, password=user.password,
photo=None, is_admin=False, coins=0)
db.add(db_user)
db.commit()
db.refresh(db_user)
return {"JWT Token": signJWT(user.email),
**user.dict()}
Here is model of my User:
class User(Base):
__tablename__ = "user"
__table_args__ = {'extend_existing': True}
id = Column(Integer, primary_key=True, index=True)
name = Column(String(50), nullable=False)
surname = Column(String(50), nullable=False)
email = Column(String(50), unique=True, nullable=False)
phone_number = Column(String(15), unique=True, nullable=False)
login = Column(String(50), unique=True, nullable=False)
password = Column(String(80), nullable=False)
photo = Column(String(80), nullable=True)
is_admin = Column(Boolean, nullable=False)
coins = Column(Integer, nullable=False)
time_created = Column(DateTime(timezone=True), server_default=func.now())
time_updated = Column(DateTime(timezone=True), onupdate=func.now())
address_id = Column(Integer, ForeignKey("address.id"), nullable=False)
address = relationship("Address", back_populates="user")
pin = relationship("Pin", back_populates="user")
payment_card = relationship("PaymentCard", back_populates="user")
order = relationship("Order", back_populates="user")
feedback = relationship("Feedback", back_populates="user")
post = relationship("Post", back_populates="user")
comment = relationship("Comment", back_populates="user")
animal = relationship("Animal", back_populates="user")
walk = relationship("Walk", back_populates="user")
and here is the error I get:
sqlalchemy.exc.InvalidRequestError: When initializing mapper mapped class Order->order, expression 'Status' failed to locate a name ('Status'). If this is a class name, consider adding this relationship() to the <class 'database.models.OrderModel.Order'> class after both dependent classes have been defined.
model of Order:
class Order(Base):
__tablename__ = "order"
__table_args__ = {'extend_existing': True}
id = Column(Integer, primary_key=True, index=True)
order_code = Column(String(15), nullable=True)
time_created = Column(DateTime(timezone=True), server_default=func.now())
time_updated = Column(DateTime(timezone=True), onupdate=func.now())
status_id = Column(Integer, ForeignKey("status.id"), nullable=False)
status = relationship("Status", back_populates="order")
payment_method_id = Column(Integer, ForeignKey("payment_method.id"), nullable=False)
payment_method = relationship("PaymentMethod", back_populates="order")
user_id = Column(Integer, ForeignKey("user.id"), nullable=False)
user = relationship("User", back_populates="order")
post_office = relationship("PostOffice", back_populates="order")
product = relationship("Product", secondary=OrderProduct, back_populates="order")
and model of Status:
class Status(Base):
__tablename__ = "status"
id = Column(Integer, primary_key=True, index=True)
name = Column(String(100), nullable=False)
time_created = Column(DateTime(timezone=True), server_default=func.now())
time_updated = Column(DateTime(timezone=True), onupdate=func.now())
order = relationship("Order", back_populates="status")
I createrd migration successfully and then db. I dont understand why it shows lack of relationship, which i created. And it appears in lines of codes which dont even use these Tables.

In order to make it work I had to import all of my modules into api file with endpoint. I don't know why but it works right now.

SQLAlchemy retriving a specific value and convert to an INT

I am trying to get the price value from my EVENTS class as an INT so that I can use it to make a booking by multiplying by the number of attendees for an event when I insert a new row in the booking table.
Tables in databse
class Event(db.Model):
__tablename__ = 'events'
id = db.Column(db.Integer, primary_key=True)
host = db.Column(db.String(80), nullable=False)
event_title = db.Column(db.String(80), nullable=False)
event_description = db.Column(db.String(80), nullable=False)
movie_name = db.Column(db.String(80), nullable=False)
movie_description = db.Column(db.String(80), nullable=False)
genre = db.Column(db.String(80), nullable=False)
movie_start_time = db.Column(db.Time(), nullable=False)
movie_end_time = db.Column(db.Time(), nullable=False)
classification = db.Column(db.String(80), nullable=False)
rating = db.Column(db.Integer(), nullable=False)
actors = db.Column(db.String(200), nullable=False)
directors = db.Column(db.String(200), nullable=False)
event_date = db.Column(db.Date(), nullable=False)
published_date = db.Column(db.Date(), nullable=False)
published_by = db.Column(db.String(80), nullable=False)
image = db.Column(db.String(60), nullable=False)
capacity = db.Column(db.Integer(), nullable=False)
address = db.Column(db.String(80), nullable=False)
status = db.Column(db.String(80), nullable=False)
price = db.Column(db.Integer(), nullable=False)
# ... Create the Comments db.relationship
# relation to call destination.comments and comment.destination
comments = db.relationship('Comment', backref='event')
class Booking(db.Model):
__tablename__ = 'bookings'
id = db.Column(db.Integer, primary_key=True, unique=True)
attendees = db.Column(db.Integer(), nullable=False)
total_price = db.Column(db.Integer(), nullable=False)
booked_at = db.Column(db.DateTime, default=datetime.now())
# foreign key
user_id = db.Column(db.Integer, db.ForeignKey('users.id'))
event_id = db.Column(db.Integer, db.ForeignKey('events.id'))
Code calling from Events table to get price and insert new row into Booking table
price = Event.query.with_entities(Event.price).filter_by(id = event)
user_name = User.query.with_entities(User.id).filter_by(name = current_user.name)
num_attendees = forms.attendees.data
print(num_attendees)
print(type(price))
booking = Booking(attendees=forms.attendees.data,
total_price= price * num_attendees,
user_id = user_name,
event_id = event)
#here the back-referencing works - comment.destination is set
# and the link is created
db.session.add(booking)
db.session.commit()
But I keep running into errors such as TypeError: unsupported operand type(s) for *: 'Row' and 'int'
Thank you

sqlalchemy.exc.InvalidRequestError: When initializing mapper mapped class

I am beginner trying to make a relational database in Flask project using SQLalchemy
This is the error that I am getting when I try to register a user:-
sqlalchemy.exc.InvalidRequestError: When initializing mapper mapped class Question->question, expression 'Answer' failed to locate a name ('Answer'). If this is a class name, consider adding this relationship() to the <class 'nothingness.models.Question'> class after both dependent classes have been defined.
DB relationships are:-
User (Many to Many) Table
User (1 to Many) Question
Question (1 to Many) Answer
Table (1 to Many) Question
Here are my codes
from datetime import datetime
from nothingness import db
members = db.Table(
"member",
db.Column("id", db.Integer, primary_key=True),
db.Column("table_id", db.Integer, db.ForeignKey("table.id")),
db.Column("user_id", db.Integer, db.ForeignKey("user.id")),
)
class User(db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(25), unique=True, nullable=False)
name = db.Column(db.String(25), nullable=False)
email = db.Column(db.String(), unique=True, nullable=False)
image_file = db.Column(db.String(20), nullable=False, default="default.jpg")
password = db.Column(db.String(60), nullable=False)
created_at = db.Column(db.DateTime, nullable=False, default=datetime.utcnow)
member = db.relationship("Table", secondary=members, backref=db.backref("members", lazy=True))
prashna = db.relationship("Question", backref="user", lazy=True)
def __repr__(self):
return f"User('{self.name}', '{self.username}', '{self.email}', '{self.image_file}')db.Model"
class Table(db.Model):
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(25), nullable=False)
key = db.Column(db.String(5), nullable=False)
created_at = db.Column(db.DateTime, nullable=False, default=datetime.utcnow)
question = db.relationship("Question", backref="questions", lazy=True)
def __repr__(self):
return f"Table('{self.id}', '{self.name}', '{self.key}', {self.created_at})"
class Question(db.Model):
id = db.Column(db.Integer, primary_key=True)
question = db.Column(db.String(255), nullable=False)
asked_by = db.Column(db.Integer, db.ForeignKey("user.id"))
asked_to = db.Column(db.Integer, nullable=False)
answer = db.relationship("Answer", backref="question", lazy=True)
table = db.Column(db.Integer, db.ForeignKey("table.id"))
created_at = db.Column(db.DateTime, nullable=False, default=datetime.utcnow)
class Answer:
id = db.Column(db.Integer, primary_key=True)
points = db.Column(db.Integer)
answer = db.Column(db.String(255), nullable=False)
answered_by = db.Column(db.Integer, nullable=False)
table_id = db.Column(db.Integer, nullable=False)
created_at = db.Column(db.DateTime, nullable=False, default=datetime.utcnow)
question = db.Column(db.Integer, db.ForeignKey("question.id"))
def __repr__(self):
return f"Answer('{self.points}', '{self.answer}', '{self.created_at}')"

This error occurred because I forgot to subclass Answer with db.Model

sqlalchemy.exc.NoReferencedTableError: Foreign key could not find table

I have some models that i'd like to migrate, 2 of them are:
FamilyMember.py
class FamilyMember(db.Model):
__tablename__ = 'family_members'
id = db.Column(db.Integer, primary_key=True)
parent_id = db.Column(db.Integer, db.ForeignKey('users.id'))
name = db.Column(db.String(120), index=True)
email = db.Column(db.String(120), index=True, unique=True)
password = db.Column(db.String(128), nullable=False)
notification = db.Column(db.Boolean, default=True)
auto_ml = db.Column(db.Boolean, default=True)
photo = db.Column(db.String(128), nullable=True)
created_at = db.Column(db.DateTime(timezone=True), server_default=db.func.now())
updated_at = db.Column(db.DateTime(timezone=True), server_default=db.func.now(), onupdate=db.func.now())
notifications = db.relationship('Notification', backref='family_members', lazy='dynamic')
And Notification.py
class Notification(db.Model):
__tablename__ = 'notifications'
id = db.Column(db.Integer, primary_key=True)
user_id = db.Column(db.Integer, db.ForeignKey('users.id'))
fm_id = db.Column(db.Integer, db.ForeignKey('family_members.id'))
text = db.Column(db.String(255))
read = db.Column(db.Boolean, default=False)
type = db.Column(db.Integer)
created_at = db.Column(db.DateTime(timezone=True), server_default=db.func.now())
updated_at = db.Column(db.DateTime(timezone=True), server_default=db.func.now(), onupdate=db.func.now())
Regarding to this post, i have to explicitly state table name with __tablename__ = 'tablename', i've done that but it didn't work the way it supposed to and still got the error sqlalchemy.exc.NoReferencedTableError: Foreign key associated with column 'notifications.fm_id' could not find table 'family_members' with which to generate a foreign key to target column 'id'. What should i do?

You can use back_populates instead of backref in db.relationship()
class Notification(db.Model):
__tablename__ = 'notifications'
id = db.Column(db.Integer, primary_key=True)
user_id = db.Column(db.Integer, db.ForeignKey('users.id'))
fm_id = db.Column(db.Integer, db.ForeignKey('family_members.id'))
text = db.Column(db.String(255))
read = db.Column(db.Boolean, default=False)
type = db.Column(db.Integer)
created_at = db.Column(db.DateTime(timezone=True), server_default=db.func.now())
updated_at = db.Column(db.DateTime(timezone=True), server_default=db.func.now(), onupdate=db.func.now())
family_members = db.relationship("FamilyMember", back_populates="notifications")
class FamilyMember(db.Model):
__tablename__ = 'family_members'
id = db.Column(db.Integer, primary_key=True)
parent_id = db.Column(db.Integer, db.ForeignKey('users.id'))
name = db.Column(db.String(120), index=True)
email = db.Column(db.String(120), index=True, unique=True)
password = db.Column(db.String(128), nullable=False)
notification = db.Column(db.Boolean, default=True)
auto_ml = db.Column(db.Boolean, default=True)
photo = db.Column(db.String(128), nullable=True)
created_at = db.Column(db.DateTime(timezone=True), server_default=db.func.now())
updated_at = db.Column(db.DateTime(timezone=True), server_default=db.func.now(), onupdate=db.func.now())
notifications = db.relationship("Notification", back_populates="family_member")

How to set relationship between two tables in SQLAlchemy?

I have got two tables:
Announcements
AnnouncementsSchedule
Relationship is one(Announcements) to many(AnnouncementsSchedule) by keys:
Announcements.id = AnnouncementsSchedule.announcements_id
I tried to describe models in SQLAlchemy:
The first table is described as model:
class Announcements(db.Model):
__tablename__ = 'announcements'
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(150), nullable=False)
text = db.Column(db.Text(), nullable=False)
category = db.Column(db.Integer(), nullable=False)
subcategory = db.Column(db.Integer(), nullable=False)
offer_type = db.Column(db.Integer(), nullable=False)
url = db.Column(db.String(150), nullable=True)
status = db.Column(db.Integer(), nullable=False)
#children = relationship("AnnouncementsSchedule", back_populates="announcements")
Second is:
class AnnouncementsSchedule(db.Model):
__tablename__ = 'announcements_schedule'
id = Column(Integer, primary_key=True)
week_day = db.Column(db.Integer(), nullable=True)
week_all = db.Column(db.Integer(), nullable=False)
time = db.Column(db.Time(), nullable=False)
announcement_id = Column(Integer, ForeignKey('announcements.announcements_id'))
What I do wrong?

You have a mistake in the column name (announcements doesn't have announcement_id ):
# announcement_id = Column(Integer, ForeignKey('announcements.announcements_id'))
# change to ->
announcement_id = Column(Integer, ForeignKey('announcements.id'))