Flask - Convert request.args to dict - sqlalchemy

Question

I've been trying to figure out how to pass the request.args to sqlalchemy filter.
I thought this should work:
model.query.filter(**request.args).all()
But it's throwing the error:
TypeError: <lambda>() got an unexpected keyword argument 'userid'
When userid or any other get arg is present.
According to this post - https://stackoverflow.com/questions/19506105/flask-sqlalchemy-query-with-keyword-as-variable - you can pass a dict to the filter function.
Any ideas what I'm doing wrong?
Many thanks :)
UPDATE: Many thanks to the poster below, however now it's throwing the following error:
ProgrammingError: (ProgrammingError) (1064, "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') ORDER BY tblclients.clientname' at line 3") 'SELECT favourites.id AS favourites_id, favourites.userid AS favourites_userid, favourites.clientid AS favourites_clientid, favourites.last_visit AS favourites_last_visit \nFROM favourites INNER JOIN tblclients ON tblclients.clientid = favourites.clientid \nWHERE favourites.userid = %s ORDER BY tblclients.clientname' ([u'41'],)
Any ideas?

Answer 1

First, you have to use filter_by, not filter.
Second, Flask request.args uses a MultiDict, a dict with the values inside a list, allowing more than one value for the same key, because the same field can appear more than once in a querystring. You got the error because the SQL query got the [u'41'] when it expected only '41'. You can use request.args.to_dict() to fix that:
model.query.filter_by(**request.args.to_dict()).all()

Answer 2

Use filter_by:
model.query.filter_by(**request.args).all()
filter is used like this: query.filter(Class.property == value) while filter_by is used like this: query.filter_by(property=value) (the first one being an expression and the latter one being a keyword argument).

Answer 3

filter_by(**request.args) doesn't work well if you have non-model query parameters, like page for pagination, otherwise you get errors like these:
InvalidRequestError: Entity '<class 'flask_sqlalchemy.JobSerializable'>' has no property 'page'
I use something like this which ignores query parameters not in the model:
builder = MyModel.query
for key in request.args:
if hasattr(MyModel, key):
vals = request.args.getlist(key) # one or many
builder = builder.filter(getattr(MyModel, key).in_(vals))
if not 'page' in request.args:
resources = builder.all()
else:
resources = builder.paginate(
int(request.args['page'])).items
Considering a model with a column called valid, something like this will work:
curl -XGET "http://0.0.0.0/mymodel_endpoint?page=1&valid=2&invalid=whatever&valid=1"
invalid will be ignored, and page is available for pagination and best of all, the following SQL will be generated: WHERE mymodel.valid in (1,2)
(get the above snippet for free if you use this boilerplate-saving module)

Answer 4

You can:
http://localhost:5000/filter-test?var=test
query_dict = request.args.to_dict()
print(query_dict)
{'var': 'test'}
print(query_dict['var'])
var