sqlalchemy

问题 I have a python script that loads , transform and calculates data. In sql-server there's a stored procedure that requires a table valued parameter, 2 required parameters and 2 optional parameters. In sql server I can call this SP: USE [InstName] GO DECLARE @return_value int DECLARE @MergeOnColumn core.MatchColumnTable INSERT INTO @MergeOnColumn SELECT 'foo.ExternalInput','bar.ExternalInput' EXEC @return_value = [core].[_TableData] @Target = N'[dbname].[tablename1]', @Source = N'[dbname].

问题 I am currently creating an engine in my DAG and passing this sqlalchemy engine as a parameter to PythonOperator to execute some database work. e.g. PythonOperator(python_callable=my_callable, op_args=[engine], provide_context=True, task_id = 'my_task', dag=dag) When I try to clear the status of tasks, I get an error File "/opt/conda/lib/python3.7/copy.py", line 169, in deepcopy rv = reductor(4) TypeError: can't pickle _thread._local objects This is most likely because you can't pickle engine

问题 I'm working with pandas and sqlalchemy, and would like to load a DataFrame into a MySQL database. I'm currently using this code snippet: db_connection = sqlalchemy.create_engine('mysql+mysqlconnector://user:pwd@hostname/db_name') some_data_ref.to_sql(con=db_connection, name='db_table_name', if_exists='replace') sqlalchemy , pandas have been imported prior to this. My MySQL backend is 8.x, which I know uses caching_sha2_password . If I were to connect to the database using mysql.connector

问题 I have a webapp that communicates with a postgres database via Flask-SQLAlchemy. The app successfully adds/updates individual images to the database. The calls to func1_add_image , func2_add_image are done via separate fetch request from javascript code. # in python db = sqlalchemy(session_options={'autocommit': False}) ... @bp.route('/api/v1_2/func1_add_image', methods=['POST']) def func1_add_image(): db.session.add(image1) db.session.commit() ... @bp.route('/api/v1_2/func2_add_image',

问题 I'm adding a bunch of entries to a table in sqlalchemy. If an entry already exists, based on some key, I delete the row in the table and then add the "updated" entry. After finishing deleting and adding all entries I commit the session. However during testing the commit fails due to a unique constraint failure. My understanding from this error is that I'm trying to add the updated entry before deleting the old entry. If I delete the old entry, then commit, then add, everything works ok. So my

问题 I already know that for general cases: this question is sufficient: SQLAlchemy set default value of one column to that of another column But when my column depends on the Id column it doesn't work because id is auto generated. For eg: Using the same example as the other question class Substance(Base): __tablename__ = "substances" id = Column(Integer, primary_key=True) code = Column(String, unique=True) name = Column(String, unique=True) subtance_hash = Column(String, unique=True, default

问题 We are trying to run a flask db migrate and flask db upgrade which throws the following error: Usage: flask db upgrade [OPTIONS] [REVISION] Error: The file/path provided (C) does not appear to exist. Please verify the path is correct. If app is not on PYTHONPATH, ensure the extension is .py We have added the app's directory to the PYTHONPATH environment variable but still get the error. Any help would be appreciated. Below is our __init__.py code. Are we missing something? import logging from

问题 I'm seeing wrong query results when executing queries against an external MySQL database, but only when connecting from Celery tasks running on Heroku. The same tasks, when run on my own machine do not show these errors, and the errors only appear about half of the time (although when they fail, all tasks are wrong). The tasks are managed by Celery via Redis, and the MySQL database does not itself run on Heroku. Both my local machine and Heroku connect to the same MySQL database. I connect to

问题 I'm having a bit of trouble with using SQLAlchemy to its full potential in a Python application using Flask, and understanding how many-to-one relationships work and how they can be utilized. I'm working with a database of songs and artists with a schema that looks like this: CREATE TABLE song ( id INTEGER PRIMARY KEY AUTO_INCREMENT, title VARCHAR(64), artist_id INTEGER ); CREATE TABLE artist ( id INTEGER PRIMARY KEY AUTO_INCREMENT, name VARCHAR(64) ); Or, through Python SQLAlchemy, it looks

问题 I have the following models in my DB (Flask-SQLALchemy, declarative approach, simplified): class Player(db.Model): id = db.Column(db.Integer, primary_key = True) ... class Game(db.Model): id = db.Column(db.Integer, primary_key = True) creator_id = db.Column(db.Integer, db.ForeignKey('player.id')) creator = db.relationship(Player, foreign_keys='Game.creator_id') opponent_id = db.Column(db.Integer, db.ForeignKey('player.id')) opponent = db.relationship(Player, foreign_keys='Game.opponent_id')