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Flask-Admin: Change sort order of inline_models?

In Flask-Admin, is there any way to control the order of the list generated by inline_models? It seems to be coming out in database order, i.e. ordered by the ID primary key.
That is, if I have an Author that has_many Books, and my AuthorModelView class has inline_models = (Books,), the books are always ordered by book_id. Passing column_default_sort to the inline model, to try to sort by (say) title or date_purchased, has no effect. Is there any way to handle this?

Specify the order_by parameter when specifying the relationships, see docs. See note at the end if you want to sort by a specific field at runtime.
Example of model declarations for Author -> Books. Here we are ordering on the book title field ascending - order_by='Book.title.asc()' :
class Author(db.Model):
__tablename__ = 'authors'
id = db.Column(db.Integer, primary_key=True)
first_name = db.Column(db.Text(length=255), nullable=False)
last_name = db.Column(db.Text(length=255), nullable=False)
books = db.relationship("Book", order_by='Book.title.asc()', cascade="all,delete-orphan", backref=db.backref('author'))
def __str__(self):
return f"ID: {self.id}; First Name: {self.first_name}; Last Name: {self.last_name}"
class Book(db.Model):
__tablename__ = 'books'
id = db.Column(db.Integer, primary_key=True)
author_id = db.Column(db.Integer, db.ForeignKey('authors.id'), nullable=False, index=True)
title = db.Column(db.Text(length=255), nullable=False)
def __str__(self):
return f"ID: {self.id}; Title: {self.title}; Author ID: {self.author_id}"
Single file full example:
from faker import Faker
import click
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_admin import Admin
from flask_admin.contrib import sqla
db = SQLAlchemy()
class Author(db.Model):
__tablename__ = 'authors'
id = db.Column(db.Integer, primary_key=True)
first_name = db.Column(db.Text(length=255), nullable=False)
last_name = db.Column(db.Text(length=255), nullable=False)
books = db.relationship("Book", order_by='Book.title.asc()', cascade="all,delete-orphan", backref=db.backref('author'))
def __str__(self):
return f"ID: {self.id}; First Name: {self.first_name}; Last Name: {self.last_name}"
class Book(db.Model):
__tablename__ = 'books'
id = db.Column(db.Integer, primary_key=True)
author_id = db.Column(db.Integer, db.ForeignKey('authors.id'), nullable=False, index=True)
title = db.Column(db.Text(length=255), nullable=False)
def __str__(self):
return f"ID: {self.id}; Title: {self.title}; Author ID: {self.author_id}"
app = Flask(__name__)
app.config['SECRET_KEY'] = '123456790'
app.config['SQLALCHEMY_ECHO'] = True
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = True
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///sample.sqlite'
db.init_app(app)
#app.cli.command('create-database', short_help='Create Authors database')
#click.option('--count', default=100, help='Number of authors (default 100)')
def create_database(count):
"""
Create database with "count" authors
"""
db.drop_all()
db.create_all()
_faker = Faker()
for _ in range(0, count):
_author = Author(
first_name=_faker.first_name(),
last_name=_faker.last_name(),
)
db.session.add(_author)
for _ in range(0, _faker.pyint(1, 20)):
_book = Book(
title=_faker.sentence(),
author=_author
)
db.session.add(_book)
db.session.commit()
class AuthorView(sqla.ModelView):
# default sort: last_name ascending
column_default_sort = ('last_name', False)
inline_models = (Book,)
# Flask views
#app.route('/')
def index():
return 'Click me to get to Admin!'
admin = Admin(app, template_mode="bootstrap3")
admin.add_view(AuthorView(Author, db.session))
if __name__ == '__main__':
app.run()
Run the following command to initialize an SQLite DB.
flask create-database --count 100
If you want to change the sort field at runtime override the view's get_one() method and use Python to sort the instrumented list directly. For example, sorting by ISBN field instead of title:
class Author2View(sqla.ModelView):
def get_one(self, id):
_author = super().get_one(id)
_author.books = sorted(_author.books, key=lambda book: book.isbn)
return _author
# default sort: last_name ascending
column_default_sort = ('last_name', False)
inline_models = (Book,)
admin.add_view(Author2View(Author, db.session, name="Author 2", endpoint='author-2'))

How to get data from two tables using SQLALCHEMY

Let say I have a model
import os
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy()
class Students(db.Model):
__tablename__ = "students"
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String, nullable=False)
description = db.Column(db.String, nullable=False)
class Hobbies(db.Model):
__tablename__ = "hobbies"
id = db.Column(db.Integer, primary_key=True)
title = db.Column(db.String, nullable=False)
description = db.Column(db.String)
student_id = db.Column(db.Integer, db.ForeignKey("students.id"), nullable=False)
Now in flask I have following code
import os
from flask import Flask, render_template, request
from models import *
app = Flask(__name__)
app.config["SQLALCHEMY_DATABASE_URI"] = "postgresql://junaid:junaid#localhost:5432/UOB"
app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
db.init_app(app)
Now I get all the record in the table Hobbies
from sqlalchemy.sql import select
with app.app_context():
a = Hobbies.query.all()
I want to get the result like
Hobby.ID, Hobby.title, Hobby.description, Student.name (The filter is Hobby.student_id = Students.id)
I want to print all the record in the hobbies table with student name in short.

Here is the solution. Sharing if someone else can benefit from this.
hobbies_with_stud = db.session.query(Students, Hobbies).join(Hobbies, Hobbies.student_id == Students.id).all()
for record in hobbies_with_stud:
print(record.Hobbies.title + " is the hobby of "+ record.Students.name)

How to query multiple items using Flask SQLAlchemy

After importing the modules:
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
and declaring app and db objects:
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///test.db'
db = SQLAlchemy(app)
I go ahead and create two tables: User and Email:
class User(db.Model):
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(50))
addresses = db.relationship('Email', backref='person', lazy='dynamic')
class Email(db.Model):
id = db.Column(db.Integer, primary_key=True)
email = db.Column(db.String(50))
person_id = db.Column(db.Integer, db.ForeignKey('user.id'))
With db.relationship in place I can now link some multiple emails to the same user. First I create two email addresses:
first_email = Email(email='first#email.com')
second_email = Email(email='second#email.com')
Then I am passing these two emails to User class at the time it is being created:
user = User(name='User Name', addresses = [first_email, second_email])
To see which user is linked to which email I can simply use:
print first_email.person
print user.addresses.all()
Now I want to add another third email to the same user. How do I append a new email to the list of the emails that have been already linked to the user?

new_email = Email(email='new_email#example.com')
user.addresses.append(new_email)
db.session.commit()
This will append the email address to the relationship.

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///inquestion.db'
db = SQLAlchemy(app)
class User(db.Model):
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(50))
addresses = db.relationship('Email', backref='person', lazy='dynamic')
def add_email(self, new_email):
linked_emails = [email.email for email in self.addresses.all()]
if not new_email in linked_emails:
linked_emails.append(new_email)
self.addresses = [Email.find_or_create(email) for email in linked_emails]
class Email(db.Model):
id = db.Column(db.Integer, primary_key=True)
email = db.Column(db.String(50))
person_id = db.Column(db.Integer, db.ForeignKey('user.id'))
#staticmethod
def find_or_create(email):
try:
return Email.query.filter_by(email=email).one()
except:
new_email = Email(email=email)
db.session.add(new_email)
db.session.commit()
return new_email
first_email = Email(email='first#email.com')
second_email = Email(email='second#email.com')
user = User(name='User Name', addresses = [first_email, second_email])
db.drop_all()
db.create_all()
db.session.add(first_email)
db.session.add(second_email)
db.session.add(user)
db.session.commit()
# some extra queries
user.add_email('third#email.com')
print user.addresses.all()
print Email.find_or_create('fourth#email.com')
print Email.query.filter_by(email='fourth#email.com').one().email
print first_email.query.filter_by(email='second#email.com').one()

understanding marshmallow nested schema with list data

Am new to python and am usign marshmallow serialization. unable to use the nested scehma.
, my code
from sqlalchemy import Column, Float, Integer, String, Text, text,ForeignKey
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
Base = declarative_base()
metadata = Base.metadata
class CompanyDemo(Base):
__tablename__ = 'company_demo'
company_id = Column(Integer, primary_key=True,
server_default=text("nextval('company_demo_company_id_seq'::regclass)"))
name = Column(Text, nullable=False)
address = Column(String(50))
location = Column(String(50))
class UsersDemo(Base):
__tablename__ = 'users_demo'
id = Column(Integer, primary_key=True,
server_default=text("nextval('users_demo_id_seq'::regclass)"))
company_id = Column(Integer,ForeignKey('company_demo.company_id'), nullable=False)
email = Column(String)
company = relationship('CompanyDemo')
schema
from marshmallow import Schema, fields, pprint
class CompanySchema(Schema):
company_id = fields.Int(dump_only=True)
name = fields.Str()
address = fields.Str()
location = fields.Str()
class UserSchema(Schema):
email = fields.Str()
company = fields.Nested(CompanySchema)
user = UserSchema()
user = UserSchema(many=True)
company = CompanySchema()
company = CompanySchema(many=True)
and my flask app
from flask import Flask, jsonify, url_for, render_template
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from flask_sqlalchemy import SQLAlchemy
from model import CompanyDemo, UsersDemo
from schemas.userschema import user, company
app = Flask(__name__)
app.secret_key = "shiva"
def db_connect():
engine = create_engine('postgresql://ss#127.0.0.1:5432/test')
Session = sessionmaker(autocommit=False, autoflush=False, bind=engine)
# create a Session
session = Session()
session._model_changes = {}
return session
#app.route('/company', methods=["GET", "POST"])
def get_all_company():
db = db_connect()
allcompany = db.query(CompanyDemo).join(UsersDemo).all()
return jsonify(company.dump(allcompany, many=True).data) # company is marshmallow schema
if __name__ == '__main__':
app.run(host='0.0.0.0', port=15418, debug=True)
anything wrong in my code? and am facing problem with nested schema and unable to get the nested data in output.
the output below
[ {
"address": "qqq ",
"company_id": 1,
"location": "www ",
"name": "eee" }, {
"address": "www ",
"company_id": 2,
"location": "qqq ",
"name": "aaa" } ]

Self contained example using in-memory SQLite:
from flask import Flask, jsonify
from flask_sqlalchemy import SQLAlchemy
from marshmallow import Schema, fields, pprint
app = Flask(__name__)
app.config['DEBUG'] = True
app.config['SECRET_KEY'] = 'super-secret'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///:memory:'
app.config['SQLALCHEMY_ECHO'] = True
db = SQLAlchemy(app)
class CompanyDemo(db.Model):
__tablename__ = 'company_demo'
company_id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.Text, nullable=False)
address = db.Column(db.String(50))
location = db.Column(db.String(50))
def __unicode__(self):
return u"{name} ({address})".format(name=self.name, address=self.address)
class UsersDemo(db.Model):
__tablename__ = 'users_demo'
id = db.Column(db.Integer, primary_key=True,)
company_id = db.Column(db.Integer, db.ForeignKey('company_demo.company_id'), nullable=False)
company = db.relationship('CompanyDemo')
email = db.Column(db.String)
def __unicode__(self):
return u"{email}".format(email=self.email)
class CompanySchema(Schema):
company_id = fields.Int(dump_only=True)
name = fields.Str()
address = fields.Str()
location = fields.Str()
class UserSchema(Schema):
email = fields.Str()
company = fields.Nested(CompanySchema)
user_schema = UserSchema()
company_schema = CompanySchema()
#app.route('/')
def index():
return "<a href='/dump_company'>Dump Company</a><br><a href='/dump_user'>Dump User</a>"
#app.route('/dump_user')
def dump_user():
user = UsersDemo.query.first()
return jsonify(user_schema.dump(user).data)
#app.route('/dump_company')
def dump_company():
company = CompanyDemo.query.first()
return jsonify(company_schema.dump(company).data)
def build_db():
db.drop_all()
db.create_all()
company = CompanyDemo(name='Test 1', address='10 Downing Street', location='wherever')
db.session.add(company)
user = UsersDemo(email='fred#example.com', company=company)
db.session.add(user)
db.session.commit()
#app.before_first_request
def first_request():
build_db()
if __name__ == '__main__':
app.run(debug=True, port=7777)

SQLAlchemy / WTForms - QuerySelectField

I'm using WTForms with the SQLAlchemy extension on a Pyramid application.
My session is:
from zope.sqlalchemy import ZopeTransactionExtension
DBSession = scoped_session(sessionmaker(extension=ZopeTransactionExtension()))
Base = declarative_base()
My model is:
class Client(Base):
__tablename__ = 'client'
id = Column(Integer, primary_key=True, nullable=False)
name = Column(Unicode(48))
street = Column(Unicode(48))
city = Column(Unicode(32))
task = relationship("Task", backref="client")
#classmethod
def active(cls):
return DBSession.query(Client).options(load_only("id", "name")).order_by(sa.desc(Client.name)).filter(Client.status == True)
class Task(Base):
__tablename__ = 'task'
id = Column(Integer, primary_key=True, nullable=False)
name = Column(String(48))
status = Column(Boolean)
client_id = Column(Integer, ForeignKey('client.id'))
My form is:
def enabled_client():
return Client.active()
class TaskCreateForm(ModelForm):
name = TextField('Task name', [validators.Length(min=1, max=48)], filters=[strip_filter])
status = BooleanField('Status')
client_id = QuerySelectField('Client', query_factory=enabled_client, get_label='name', allow_blank=False)
My view is:
#view_config(route_name='task_action', match_param='action=create', renderer='arx:templates/task_edit.mako', permission='edit')
def task_create(request):
task = Task()
form = TaskCreateForm(request.POST)
if request.method == 'POST' and form.validate():
form.populate_obj(task)
DBSession.add(task)
return HTTPFound(location=request.route_url('home'))
return {'form':form, 'action':request.matchdict.get('action')}
Form displays select box with proper Client names but the problem emerges when I'm trying to submit form. WTForm should use real ID of Client but it passes SQLAlchemy object eg:
<arx.models.Client object at 0x7fdfb139ddd0>
What am I doing wrong?

My form was too specific (it should be client instead of client_id), so my working code looks like this:
Session:
from zope.sqlalchemy import ZopeTransactionExtension
DBSession = scoped_session(sessionmaker(extension=ZopeTransactionExtension()))
Base = declarative_base()
Model:
class Client(Base):
__tablename__ = 'client'
id = Column(Integer, primary_key=True, nullable=False)
name = Column(Unicode(48))
street = Column(Unicode(48))
city = Column(Unicode(32))
task = relationship("Task", backref="client")
#classmethod
def active(cls):
return DBSession.query(Client).options(load_only("id", "name")).order_by(sa.desc(Client.name)).filter(Client.status == True)
class Task(Base):
__tablename__ = 'task'
id = Column(Integer, primary_key=True, nullable=False)
name = Column(String(48))
status = Column(Boolean)
client_id = Column(Integer, ForeignKey('client.id'))
Form:
def enabled_client():
return Client.active()
class TaskCreateForm(ModelForm):
name = TextField('Task name', [validators.Length(min=1, max=48)], filters=[strip_filter])
status = BooleanField('Status')
client = QuerySelectField('Client', query_factory=enabled_client, get_label='name', allow_blank=False)
View:
#view_config(route_name='task_action', match_param='action=create', renderer='arx:templates/task_edit.mako', permission='edit')
def task_create(request):
task = Task()
form = TaskCreateForm(request.POST)
if request.method == 'POST' and form.validate():
form.populate_obj(task)
DBSession.add(task)
return HTTPFound(location=request.route_url('home'))
return {'form':form, 'action':request.matchdict.get('action')}