flask sqlalchemy query with keyword as variable

by

SQLAlchemy’s filter_by takes keyword arguments:

filter_by(**kwargs)

In other words, the function will allow you to give it any keyword parameter. This is why you can use any keyword that you want in your code: SQLAlchemy basically sees the arguments a dictionary of values. See the Python tutorial for more information on keyword arguments.

So that allows the developers of SQLAlchemy to receive an arbitrary bunch of keyword arguments in a dictionary form. But you’re asking for the opposite: can you pass an arbitrary bunch of keyword arguments to a function?

It turns out that in Python you can, using a feature called unpacking. Simply create the dictionary of arguments and pass it to the function preceded by **, like so:

kwargs = {'hometown': 'New York', 'university' : 'USC'}
User.query.filter_by(**kwargs)
# This above line is equivalent to saying...
User.query.filter_by(hometown='New York', university='USC')

More Related Contents:

  1. How to execute raw SQL in Flask-SQLAlchemy app
  2. jsonify a SQLAlchemy result set in Flask [duplicate]
  3. How to build a flask application around an already existing database?
  4. Flask sqlalchemy many-to-many insert data
  5. How to delete a record by id in Flask-SQLAlchemy
  6. Get inserted key before commit session
  7. Querying with function on Flask-SQLAlchemy model gives BaseQuery object is not callable error
  8. AttributeError: ‘int’ object has no attribute ‘_sa_instance_state’
  9. Getting first row from sqlalchemy
  10. flask-sqlalchemy or sqlalchemy
  11. Flask-SQLAlchemy Constructor
  12. SQLAlchemy ordering by count on a many to many relationship
  13. SQLAlchemy ORM conversion to pandas DataFrame
  14. How do I get a raw, compiled SQL query from a SQLAlchemy expression?
  15. sqlalchemy: how to join several tables by one query?
  16. Serve image stored in SQLAlchemy LargeBinary column
  17. Implementing Flask-Login with multiple User Classes
  18. Can SQLAlchemy be used with Google Cloud SQL?
  19. Updates to JSON field don’t persist to DB
  20. Complex foreign key constraint in SQLAlchemy
  21. ImportError: No module named MySQLdb
  22. Is a SQLAlchemy query vulnerable to injection attacks?
  23. SQLAlchemy: how to filter date field?
  24. How to execute “left outer join” in SqlAlchemy
  25. Getting random row through SQLAlchemy
  26. Select NULL Values in SQLAlchemy
  27. Using SQLAlchemy models in and out of Flask
  28. Flask, SQLAlchemy : KeyError: ‘SQLALCHEMY_TRACK_MODIFICATIONS’
  29. Retrieve query results as dict in SQLAlchemy
  30. Tyring to set up modelview with Flask-Admin causes ImportError

Leave a Comment