Question

所以基本上我已经在几个小时内遇到这个flask_sqlachemy错误，尝试了多种解决方案在线，但是虽然我是这种语言和框架的新手，但是却无法正常工作。 sqlalchemy.exc.InvalidRequestError：表“处理”已定义此MetaData实例。指定'extend_existing = True'重新定义现有Table对象上的选项和列。

这是我的main.py
＃main.py

from app import app
from db_setup import init_db, db_session
from forms import VisitSearchForm, TreatmentForm, PatientForm
from flask import flash, render_template, request, redirect
from models import Treatment, Visit, init_db, Patient
from tables import Results
from app import db
init_db()


@app.route('/', methods=['GET', 'POST'])
def index():
search = VisitSearchForm(request.form)
if request.method == 'POST':
    return search_results(search)

return render_template('index.html', form=search)


@app.route('/results')
def search_results(search):
results = []
search_string = search.data['search']

if search.data['search'] == '':
    qry = db_session.query(Treatment, Patient)
    results = qry.all()

if not results:
    flash('No results found!')
    return redirect('/')
else:
    # display results
    table = Results(results)
    table.border = True
    return render_template('results.html', table=table)

@app.route('/new_treatment', methods=['GET', 'POST'])
def new_treatment():
"""
Add a new treatment
"""
form = TreatmentForm(request.form)

if request.method == 'POST' and form.validate():
    # save the treatment
    treatment = Treatment()
    save_changes(treatment, form, new=True)
    flash('Treatment Added successfully!')
    return redirect('/')

return render_template('new_treatment.html', form=form)

@app.route('/new_patient', methods=['GET', 'POST'])
def new_patient():
"""
Add a new treatment
"""
form = PatientForm(request.form)

if request.method == 'POST' and form.validate():
    # save the treatment
    patient = Patient()
    save_changes(patient, form, new=True)
    flash('Patient Added successfully!')
    return redirect('/')

return render_template('new_patient.html', form=form)



def save_changes(treatment, patient, form, new=False):
"""
Save the changes to the database
"""
# Get data from form and assign it to the correct attributes
# of the SQLAlchemy table object
visit = Visit()
visit.name = form.visit.data

patient.name = form.name.data
patient.address = form.address.data
patient.complaint = form.complaint.data
patient.email = form.email.data

treatment.visit = visit
treatment.name = form.name.data
treatment.treatment_date = form.treatment_date.data
treatment.notes = form.notes.data
treatment.price = form.price.data
treatment.treatment_type = form.treatment_type.data
db.create_all()
if new:
    # Add the new treatment to the database
    db_session.add(treatment)

# commit the data to the database
db_session.commit()

@app.route('/item/<int:id>', methods=['GET', 'POST'])
def edit(id):
qry = db_session.query(Treatment).filter(
            Treatment.id==id)
treatment = qry.first()

if treatment:
    form = TreatmentForm(formdata=request.form, obj=treatment)
    if request.method == 'POST' and form.validate():
        # save edits
        save_changes(treatment, form)
        flash('Visit updated successfully!')
        return redirect('/')
    return render_template('edit_visit.html', form=form)
else:
    return 'Error loading #{id}'.format(id=id)

@app.route("/delete/<int:id>")
def delete(id):
Treatment.query.filter(Treatment.id == id).delete()
db.session.commit()
flash('Treatment Deleted successfully')
return redirect("/")


if __name__ == '__main__':
import os
if 'WINGDB_ACTIVE' in os.environ:
    app.debug = False
app.run(port=5001)

这是我的模型。py

from app import db

class Visit(db.Model):
__tablename__ = "visits"

id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String)

def __repr__(self):
    return "{}".format(self.name)


class Treatment(db.Model):
""""""
__tablename__ = "treatments"

id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String)
treatment_date = db.Column(db.String)
notes = db.Column(db.String)
treatment_type = db.Column(db.String)
price = db.Column(db.String)

visit_id = db.Column(db.Integer, db.ForeignKey("visits.id"))
visit = db.relationship("Visit", backref=db.backref(
    "treatments", order_by=id), lazy=True)

class Patient(db.Model):
""""""
__tablename__ = "treatments"

id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String)
address = db.Column(db.String)
complaint = db.Column(db.String)
email = db.Column(db.String)


def init_db():
db.create_all()


if __name__ == '__main__':
init_db()

db_setup.py

from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session, sessionmaker
from sqlalchemy.ext.declarative import declarative_base

engine = create_engine('sqlite:///patient.db', convert_unicode=True)
db_session = scoped_session(sessionmaker(autocommit=False,
                                     autoflush=False,
                                     bind=engine))
Base = declarative_base()
Base.query = db_session.query_property()

def init_db():
import models
Base.metadata.create_all(bind=engine)

db_creator.py

from sqlalchemy import create_engine, ForeignKey
from sqlalchemy import Column, Date, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship, backref

engine = create_engine('sqlite:///patient.db', echo=True)
Base = declarative_base()



class Visit(Base):
__tablename__ = "visits"

id = Column(Integer, primary_key=True)
name = Column(String)

def __repr__(self):
    return "<Visit: {}>".format(self.name)


class Treatment(Base):
""""""
__tablename__ = "treatments"

id = Column(Integer, primary_key=True)
name = Column(String)
treatment_date = Column(String)
notes = Column(String)
price = Column(String)
treatment_type = Column(String)

visit_id = Column(Integer, ForeignKey("visits.id"))
visit = relationship("Visit", backref=backref(
    "treatments", order_by=id))



class Patient(Base):
""""""
__tablename__ = "patients"

id = Column(Integer, primary_key=True)
name = Column(String)
address = Column(String)
complaint = Column(String)
email = Column(String)



# create tables

Base.metadata.create_all(engine)

app.py

# app.py
from models import Treatment, Visit, init_db, Patient
from flask import Flask
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///patient.db'
app.secret_key = "flask method"

db = SQLAlchemy(app)

Answer 1

似乎在您的models.py文件中，您同时为__tablename__和Treatment模型提供了相同的Patient属性。因此，存在冲突，因为两个表都试图将它们与相同的MetaData

sqlalchemy.exc.InvalidRequestError：表已定义

1 个答案: