python - SQLALchemy dynamic filter_by

Question

I know you can build dynamic filters for queries for SQLAlchemy by supplying **kwargs to filter_by.

For example

    filters = {'id': '123456', 'amount': '232'}
    db.session.query(Transaction).filter_by(**filters)

Below is my question:

What if I need to query by "greater than" or "less than" clauses? For example (raw SQL):

 select * from transaction t 
 where t.amount > 10 and t.amount < 100;

Answer 1

Instead of using filter_by I would recommend using filter, it gives you a lot more options.

For example (from the manual):

db.session.query(MyClass).filter(
    MyClass.name == 'some name',
    MyClass.id > 5,
)

In relation to your case:

filters = (
    Transaction.amount > 10,
    Transaction.amount < 100,
)
db.session.query(Transaction).filter(*filters)