since you need to track removals also I would likely keep track of individual
data manipulation operations on the data from the point that it's loaded til
the point that it's persisted again.
The SQLAlchemy ORM's "unit of work" does exactly this, in fact, so if you
loaded 25 Ingredient
For the sake of completeness I am including the code to disconnect an
option from a machine using only python/SQLite code.
def removeOption(bladeKey, OptionKey):
"""
DELETE from blade_options
WHERE blade_FK == ?
AND options_FK == ?
"""
import sqlite3
dbPath =
The situation is that I have two preloaded tables. The first is a Machine
to which one or more Options can be added. The second table has Options
can be connected to two or more machines. I've got the code to connect a
machine with an option but I can't devise the code to reverse the
Thanks. IIRC, I think you just need to set a custom cascade on these
relationships (see https://docs.sqlalchemy.org/en/13/orm/cascades.html)
I am not sure which option that would be, because it sounds like your
application is behaving with a "delete-orphan", but that's not set.
--
SQLAlchemy
full model for these 3 classes:
# machine
class Machine(Base):
__tablename__ = 'machine'
machine_ID = Column(Integer, primary_key=True)
machine_Type = Column(Integer, nullable=False)
machine_model = Column(String(10), nullable=False)
machine_Weight = Column(Integer)
Can you share the full model for these 3 classes, which includes the
relationship declarations?
--
SQLAlchemy -
The Python SQL Toolkit and Object Relational Mapper
http://www.sqlalchemy.org/
To post example code, please provide an MCVE: Minimal, Complete, and Verifiable
Example. See
I am developing a small cooking recipe application. I have a problem when
it comes to updating data taken from a table (QTbableWidget). The updated
data may contain more rows than the original already in the database ( or
less).
I usually use a dictionary with the keys corresponding to the
I am working on an app using python3 and SqlAlchemy for SQLite3 database
management. I have some tables that have a Many to Many relationship. I've
created an association table to handle this relationship.
Class Machine(Base):
__tablename__ 'machine'
machine_ID = Column(Integer,
