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How do I query resources in the nested collection in eve-sqlalchemy?

I am using Eve-SQLAlchemy==0.5.0
I would like to perform a nested query using Postman on my users such that I find all users that are within a specified organization.
Using SQL I would write my query such that:
select * from app_user
left join user_organization on user_organization.user_id = app_user.id
left join organization on organization.id = user_organization.organization_id
where organization.id = 2
I have a user model, an organization model, and a relational model linking the two user_organization.
from sqlalchemy import Column, DateTime, func, String, Integer
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class BaseModel(Base):
id = Column(Integer, primary_key=True, autoincrement=True)
__abstract__ = True
_created = Column(DateTime, default=func.now())
_updated = Column(DateTime, default=func.now(), onupdate=func.now())
_etag = Column(String(40))
class User(BaseModel):
__tablename__ = 'app_user'
organizations = relationship("Organization", secondary=UserOrganization.__tablename__)
class Organization(BaseModel):
__tablename__ = 'organization'
name = Column(String)
class UserOrganization(BaseModel):
__tablename__ = 'user_organization'
user_id = Column(Integer,
ForeignKey('app_user.id', ondelete='CASCADE'))
organization_id = Column(Integer,
ForeignKey('organization.id', ondelete='CASCADE'))
In my settings.py I have the resources registered:
# Resource Registration
DOMAIN = DomainConfig({
'organization': ResourceConfig(Organization),
'user': ResourceConfig(User)
}).render()
I have a series of postman collections setup, and using a GET request I can easily query any attribute... GET localhost:5000/user?where={"id":1}
I have tried (amongst many other things):
GET user?where={"organizations": {"organization_id" :2 }}
GET user?where={"organizations": 2}

It seems it's not possible at the moment due to a bug. I will try to fix it within the next week.
The code in https://github.com/pyeve/eve-sqlalchemy/blob/master/eve_sqlalchemy/parser.py#L73 is causing a GET ?where={"organizations": 2} to result in a SQL expression like user_id = 42 AND organization_id = 42 is generated. Which rarely makes any sense.

How to specify the join condition on a many-to-many relationship using SQLAlchemy

Here is my model:
user_map = Table(
"user_map",
Column('user_id', Integer, ForeignKey('user.id'), primary_key=True),
Column('map_id', Integer, ForeignKey('map.id'), primary_key=True),
PrimaryKeyConstraint('user_id', 'map_id', name='pk_user_map')
)
class Map(Base):
id = Column(Integer, primary_key=True)
name = Column(String)
owner_id = Column(Integer, ForeignKey('user.id'))
shared_maps = relationship(
'User',
secondary=user_map,
backref=backref('maps', lazy='dynamic')
)
class User(Base):
id = Column(Integer, primary_key=True)
name = Column(String)
email = Column(String, unique=True)
shared_maps = Map.query.filter(Map.shared_maps.any()).all()
I want to query the user_map table, using the join condition "Map.id == user_map.map_id", but SQLAlchemy is trying to join using "Map.id == user_map.map_id and Map.owner_id == user_map.user_id". How can I specify my join condition?
I tried to use primaryjoin attribute in the relationship and to specify the condition inside the .join() but without success. Thanks in advance!

Based on your code, I've rebuilt the setup; I guess your relationships were mixed up. Furthermore, I've hardly ever seen primary keys (or PrimaryKeyConstraints) in sqlalchemy's many-to-many association tables. It may make sense from a non-orm perspective, but as far as I know, it is unusual or even not required at all.
import sqlalchemy as sa
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship, sessionmaker
Base = declarative_base()
UsersXMaps = sa.Table(
'users_x_maps',
Base.metadata,
sa.Column('user', sa.Integer, sa.ForeignKey('users.id')),
sa.Column('map', sa.Integer, sa.ForeignKey('maps.id'))
)
class User(Base):
__tablename__ = 'users'
id = sa.Column(sa.Integer, primary_key=True)
name = sa.Column(sa.String)
mail = sa.Column(sa.String, unique=True)
own_maps = relationship('Map', back_populates='owner')
maps = relationship(
'Map',
secondary=UsersXMaps,
back_populates='users'
)
def __str__(self):
return '{} ({}) with {} maps'.format(
self.name, self.mail, len(self.own_maps))
class Map(Base):
__tablename__ = 'maps'
id = sa.Column(sa.Integer, primary_key=True)
name = sa.Column(sa.String)
owner_id = sa.Column(sa.Integer, sa.ForeignKey('users.id'))
owner = relationship('User', back_populates='own_maps')
users = relationship(
'User',
secondary=UsersXMaps,
back_populates='maps'
)
def __str__(self):
return '{} (by {})'.format(self.name, self.owner.name)
So far for the setup; I've extended it a bit for proper output when printing strings. Additionally, your Map.shared_maps relationship actually refers to Users, not Maps, so I also renamed that one.
When binding your association table to the two classes, you can refer to it from both sides (even though back_populates seems to overwrite/replace the original definition) - this simplifies joins from either side.
Executing the following works as expected:
if __name__ == '__main__':
engine = sa.create_engine('sqlite:///usermaps.db')
sfactory = sessionmaker(engine)
session = sfactory()
Base.metadata.create_all(bind=engine)
bilbo = User(id=1, name='Bilbo', mail='bilbo#shire.nz')
frodo = User(id=2, name='Frodo', mail='frodo#shire.nz')
mordor = Map(id=1, name='Mordor', owner=frodo, users=[bilbo, frodo])
gondor = Map(id=2, name='Gondor', owner=bilbo, users=[bilbo, frodo])
rohan = Map(id=3, name='Rohan', owner=bilbo, users=[bilbo, frodo])
session.add_all([frodo, bilbo, mordor, gondor, rohan])
session.commit()
print('Maps by owner:')
for owner in [bilbo, frodo]:
print(owner)
for item in session.query(Map).filter(Map.owner == owner).all():
print(' - ' + str(item))
print('Maps by users:')
for item in session.query(Map).filter(Map.users.any()).all():
print(' - ' + str(item))
The output is:
Maps by owner:
Bilbo (bilbo#shire.nz) with 2 maps
- Gondor (by Bilbo)
- Rohan (by Bilbo)
Frodo (frodo#shire.nz) with 1 maps
- Mordor (by Frodo)
Maps by users:
- Mordor (by Frodo)
- Gondor (by Bilbo)
- Rohan (by Bilbo)

How can I make property comparison able to be compiled to SQL expression in SQLAlchemy?

There are two tables that one column of table A is pointing another table B's primary key.
But they are placed in different database, so I cannot configure them with foreign key.
Configuring via relationship() is unavailable, so I implemented property attribute manually.
class User(Base):
__tablename__ = 'users'
id = Column(BigInteger, id_seq, primary=True)
name = Column(Unicode(256))
class Article(Base):
__tablename__ = 'articles'
__bind_key__ = 'another_engine'
# I am using custom session configures bind
# each mappers to multiple database engines via this attribute.
id = Column(BigInteger, id_seq, primary=True)
author_id = Column(BigInteger, nullable=False, index=True)
body = Column(UnicodeText, nullable=False)
#property
def author(self):
_session = object_session(self)
return _session.query(User).get(self.author_id)
#author.setter
def author(self, user):
if not isinstance(user, User):
raise TypeError('user must be a instance of User')
self.author_id = user.id
This code works well for simple operations. But it causes dirty queries making SQLAlchemy's features meaningless.
Code would be simple if it was configured via relationship() (e.g. query.filter(author=me)) got messed up(e.g. query.filter(author_id=me.id)).
Relationship(e.g. join) related features are never able to be used in query building.
Can I use property attribute, at least, in building query criterion(filter()/filter_by())?

you can still use relationship here. If you stick to "lazy loading", it will query for the related item in database B after loading the lead item in database A. You can place a ForeignKey() directive in the Column, even if there isn't a real one in the database. Or you can use primaryjoin directly:
class User(Base):
__tablename__ = 'users'
id = Column(BigInteger, id_seq, primary=True)
name = Column(Unicode(256))
class Article(Base):
__tablename__ = 'articles'
__bind_key__ = 'another_engine'
id = Column(BigInteger, id_seq, primary=True)
author_id = Column(BigInteger, nullable=False, index=True)
body = Column(UnicodeText, nullable=False)
author = relationship("User",
primaryjoin="foreign(Article.author_id) == User.id")

SQLAlchemy: retrieve all episodes from favorite_series of specific user

I have user who can have his favorite series and there are episodes which have series as foreign key and I am trying to retrieve all episodes from favorite series of user.
I am using Flask-SQLAlchemy.
Database:
db = SQLAlchemy(app)
# cross table for user-series
favorite_series = db.Table('favorite_series',
db.Column('user_id', db.Integer, db.ForeignKey('user.id')),
db.Column('series_id', db.Integer, db.ForeignKey('series.id'))
)
# user
class User(db.Model):
__tablename__ = 'user'
id = db.Column(db.Integer, primary_key=True)
favorite_series = db.relationship('Series', secondary=favorite_series,
backref=db.backref('users', lazy='dynamic'))
# series
class Series(db.Model):
__tablename__ = 'series'
id = db.Column(db.Integer, primary_key=True)
# episode
class Episode(db.Model):
__tablename__ = 'episode'
id = db.Column(db.Integer, primary_key=True)
series_id = db.Column(db.Integer, db.ForeignKey('series.id'))
series = db.relationship('Series',
backref=db.backref('episodes', lazy='dynamic'))
Friend helped me with SQL
select user_id,series.name,episode.name from (favorite_series left join series on favorite_series.series_id = series.id) left join episode on episode.series_id = series.id where user_id=1;
Altough, I want it in SQLAlchemy API, but can't manage to get it working.
EDIT:
My final working result:
episodes = Episode.query.filter(Episode.series_id.in_(x.id for x in g.user.favorite_series)).filter(Episode.air_time!=None).order_by(Episode.air_time)

First of all you don't seem to be declaring your table names?
Also, the whole point of bothering with orm is so you never have to write sql queries:
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import orm
import sqlalchemy as db
Base = declarative_base()
favorite_series = db.Table('favorite_series', Base.metadata,
db.Column('user_id', db.Integer, db.ForeignKey('User.id')),
db.Column('series_id', db.Integer, db.ForeignKey('Series.id'))
)
class Episode(Base):
__tablename__ = 'Episode'
id = db.Column(db.Integer, primary_key=True)
season = db.Column(db.Integer)
episode_num = db.Column(db.Integer)
series_id = db.Column(db.Integer, db.ForeignKey('Series.id'))
def __init__(self, season, episode_num, series_id):
self.season = season
self.episode_num = episode_num
self.series_id = series_id
def __repr__(self):
return self.series.title + \
' S' + str(self.season) + \
'E' + str(self.episode_num)
class Series(Base):
__tablename__ = 'Series'
id = db.Column(db.Integer, primary_key=True)
title = db.Column(db.String)
episodes = orm.relationship('Episode', backref='series')
def __init__(self, title):
self.title = title
def __repr__(self):
return self.title
class User(Base):
__tablename__ = 'User'
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String)
favorite_series = orm.relationship('Series',
secondary=favorite_series, backref='users')
def __init__(self, name):
self.name = name
def __repr__(self):
return self.name
Now you can just access the attributes of your objects and let sql alchemy deal with keeping you DB in sync and issuing queries.
engine = db.create_engine('sqlite:///:memory:')
session = orm.sessionmaker(bind=engine)()
Base.metadata.create_all(engine)
lt = User('Ludovic Tiako')
the_wire = Series('The Wire')
friends = Series('Friends')
session.add_all([lt, the_wire, friends])
session.commit() # need to commit here to generate the id fields
tw_s01e01 = Episode(1,1,the_wire.id)
tw_s01e02 = Episode(1,2,the_wire.id)
f_s01e01 = Episode(1,1,friends.id)
f_s01e02 = Episode(1,2,friends.id)
f_s01e03 = Episode(1,3,friends.id)
session.add_all([tw_s01e01, tw_s01e02,
f_s01e01, f_s01e02, f_s01e03])
session.commit()
the_wire.episodes # > [The Wire S1E1, The Wire S1E2]
friends.episodes # > [Friends S1E1, Friends S1E2, Friends S1E3]
Finally, to answer your question:
lt.favorite_series.append(the_wire)
session.commit()
lt.favorite_series # > [The Wire]
[s.episodes for s in lt.favorite_series] # >> [[The Wire S1E1, The Wire S1E2]]

I don't know about Flask, but from the docs of Flask-SQLAlchemy, it seems it uses declarative, so the ORM. And so, you should have a session. I think it is accessible to you from db.session.
Anyway, if those assumptions are true, this is how you should do it:
query = db.session.query(User.id, Series.name, Episode.name).filter((Episode.series_id == Series.id) & \
(User.id == favorite_series.c.user_id) & (Series.id == favorite_series.c.id) & \
(User.id == 1))
results = query.all();
It might not be the exact query you provided, but should do the same.
UPDATE: I just checked Flask-SQLALchemy code on github, it seems that db is an instance of SQLAlchemy, which has a session attribute, created by self.session = self.create_scoped_session(session_options) which returns a session object. So this should work.
Also, not that by doing that, you won't be using their BaseQuery, although I don't know what that would mean...
Check the documentation to know what to do exactly.

How to build many-to-many relations using SQLAlchemy: a good example

I have read the SQLAlchemy documentation and tutorial about building many-to-many relation but I could not figure out how to do it properly when the association table contains more than the 2 foreign keys.
I have a table of items and every item has many details. Details can be the same on many items, so there is a many-to-many relation between items and details
I have the following:
class Item(Base):
__tablename__ = 'Item'
id = Column(Integer, primary_key=True)
name = Column(String(255))
description = Column(Text)
class Detail(Base):
__tablename__ = 'Detail'
id = Column(Integer, primary_key=True)
name = Column(String)
value = Column(String)
My association table is (It's defined before the other 2 in the code):
class ItemDetail(Base):
__tablename__ = 'ItemDetail'
id = Column(Integer, primary_key=True)
itemId = Column(Integer, ForeignKey('Item.id'))
detailId = Column(Integer, ForeignKey('Detail.id'))
endDate = Column(Date)
In the documentation, it's said that I need to use the "association object". I could not figure out how to use it properly, since it's mixed declarative with mapper forms and the examples seem not to be complete. I added the line:
details = relation(ItemDetail)
as a member of Item class and the line:
itemDetail = relation('Detail')
as a member of the association table, as described in the documentation.
when I do item = session.query(Item).first(), the item.details is not a list of Detail objects, but a list of ItemDetail objects.
How can I get details properly in Item objects, i.e., item.details should be a list of Detail objects?

From the comments I see you've found the answer. But the SQLAlchemy documentation is quite overwhelming for a 'new user' and I was struggling with the same question. So for future reference:
ItemDetail = Table('ItemDetail',
Column('id', Integer, primary_key=True),
Column('itemId', Integer, ForeignKey('Item.id')),
Column('detailId', Integer, ForeignKey('Detail.id')),
Column('endDate', Date))
class Item(Base):
__tablename__ = 'Item'
id = Column(Integer, primary_key=True)
name = Column(String(255))
description = Column(Text)
details = relationship('Detail', secondary=ItemDetail, backref='Item')
class Detail(Base):
__tablename__ = 'Detail'
id = Column(Integer, primary_key=True)
name = Column(String)
value = Column(String)
items = relationship('Item', secondary=ItemDetail, backref='Detail')

Like Miguel, I'm also using a Declarative approach for my junction table. However, I kept running into errors like
sqlalchemy.exc.ArgumentError: secondary argument <class 'main.ProjectUser'> passed to to relationship() User.projects must be a Table object or other FROM clause; can't send a mapped class directly as rows in 'secondary' are persisted independently of a class that is mapped to that same table.
With some fiddling, I was able to come up with the following. (Note my classes are different than OP's but the concept is the same.)
Example
Here's a full working example
from sqlalchemy import create_engine, Column, Integer, String, ForeignKey
from sqlalchemy.orm import declarative_base, relationship, Session
# Make the engine
engine = create_engine("sqlite+pysqlite:///:memory:", future=True, echo=False)
# Make the DeclarativeMeta
Base = declarative_base()
class User(Base):
__tablename__ = "users"
id = Column(Integer, primary_key=True)
name = Column(String)
projects = relationship('Project', secondary='project_users', back_populates='users')
class Project(Base):
__tablename__ = "projects"
id = Column(Integer, primary_key=True)
name = Column(String)
users = relationship('User', secondary='project_users', back_populates='projects')
class ProjectUser(Base):
__tablename__ = "project_users"
id = Column(Integer, primary_key=True)
notes = Column(String, nullable=True)
user_id = Column(Integer, ForeignKey('users.id'))
project_id = Column(Integer, ForeignKey('projects.id'))
# Create the tables in the database
Base.metadata.create_all(engine)
# Test it
with Session(bind=engine) as session:
# add users
usr1 = User(name="bob")
session.add(usr1)
usr2 = User(name="alice")
session.add(usr2)
session.commit()
# add projects
prj1 = Project(name="Project 1")
session.add(prj1)
prj2 = Project(name="Project 2")
session.add(prj2)
session.commit()
# map users to projects
prj1.users = [usr1, usr2]
prj2.users = [usr2]
session.commit()
with Session(bind=engine) as session:
print(session.query(User).where(User.id == 1).one().projects)
print(session.query(Project).where(Project.id == 1).one().users)
Notes
reference the table name in the secondary argument like secondary='project_users' as opposed to secondary=ProjectUser
use back_populates instead of backref
I made a detailed writeup about this here.

Previous Answer worked for me, but I used a Class base approach for the table ItemDetail. This is the Sample code:
class ItemDetail(Base):
__tablename__ = 'ItemDetail'
id = Column(Integer, primary_key=True, index=True)
itemId = Column(Integer, ForeignKey('Item.id'))
detailId = Column(Integer, ForeignKey('Detail.id'))
endDate = Column(Date)
class Item(Base):
__tablename__ = 'Item'
id = Column(Integer, primary_key=True)
name = Column(String(255))
description = Column(Text)
details = relationship('Detail', secondary=ItemDetail.__table__, backref='Item')
class Detail(Base):
__tablename__ = 'Detail'
id = Column(Integer, primary_key=True)
name = Column(String)
value = Column(String)
items = relationship('Item', secondary=ItemDetail.__table__, backref='Detail')