Hello everybody!
What I want sometimes is to query some columns but to map the resulting
rows into custom data classes rather than tuples, like with
values(*columns), or SQLA entities.
I found that Bundles
(https://docs.sqlalchemy.org/en/latest/orm/loading_columns.html#bundles)
could potentially help, but what I see there is that I can process rows
with create_row_processor and give the immediate result of one-to-one
converting every single row.
Let's say I have User and Address with 1:N relation:
class User(Base):
__tablename__ = 'users'
id = Column(Integer, primary_key=True)
name = Column(String)
addresses = relationship('Address')
class Address(Base):
__tablename__ = 'addresses'
id = Column(Integer, primary_key=True)
user_id = Column(ForeignKey(User.id))
city = Column(String)
I'd like to query all users into a custom structure like this:
[{
'id': 1,
'name': 'User 1',
'addresses': [{
'id': 1,
'city': 'City 1',
}, {
'id': 2,
'city': 'City 2',
}],
}, {
'id': 2,
'name': 'User 2',
'addresses': [{
'id': 3,
'city': 'City 3',
}],
}]
It's similar to what ORM does for me when using joinedload for
relationships, but how to nest related items without ORM identity-mapped
classes?
Your help would be much appreciated!
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