Order search results by column

Anvil Q&A
1

I’m trying to get the results in descending numeric order.

data = {}
column = query["keywords"]
order = tables.order_by(column, ascending=False)
params = {column: q.greater_than(0)}
for row in app_tables.nutricalc.client_readable(q.only_cols("Food", column)).search(order, **params):
    data[row["Food"]] = row[column]
2

It would be really helpful if you tell us what exactly is not working with your current code. It seems fine so far.

1 Like
3

For these columns: food, nutrient1, nutrient2… I want to get the foods with the highest values for a nutrient in descending order.
With the above code the values in the nutrient column are not ordered.

4

What is the data type of the nutrient column?

5

Food is text, nutrients are number.

1 Like
6

Could you give an example of

  1. Your unsorted data (only what’s needed to illustrate the problem)
  2. How your code currently sorts it
  3. How you want it sorted
7

The issue is with returned data, same as here:

8

Si you still need an answer, it is the answer on that post good for you?

9

I tried this client module:

DictHelpers

import anvil.server

try:
  from functools import wraps
except:
  wraps = lambda f: f

@anvil.server.portable_class
class odict(dict):
    def __serialize__(self, global_data):
        return list(self.items())
    def __deserialize__(self, data, global_data):
        self.__init__(data)
  

def convert_to_odict(arg):
  """only worry about nested dicts, lists and tuples"""
  if isinstance(arg, dict):
    od = odict()
    for key, val in arg.items():
      od[key] = convert_to_odict(val)
    return od
  elif isinstance(arg, (list, tuple)):
    l = []
    for val in arg:
      l.append(convert_to_odict(val))
    return l
  else:
    return arg


def preserve_dict_order(f):
  @wraps(f)
  def wrapper(*args, **kwargs):
    return convert_to_odict(f(*args, **kwargs))
  return wrapper

def serialize_args(*args):
  return convert_to_odict(args)

My code:

from .DictHelpers import preserve_dict_order

@preserve_dict_order
def return_ordered(obj):
  return obj

@anvil.server.route("/serverpage")
def servercall():
    query = anvil.server.request.body_json
    data = get_data(query)
    if len(data) > 0:
      #return data
      return_ordered(data)

It returns null.

11

request.body_json only contains data for well formed requests with Content-Type: application/json. Perhaps your problem is there.

What is get_data?

Are you trying to get a dict with the keys in the same order it was sent through a json request?

If this is the case, then (1) you should have stated this at the beginning and (2) this is a lot to ask. There are many moving parts and (as far as I know) none of them explicitly says in their documentation that a request preserves the order of the keys. A dictionary is converted to json, serialized in a request, sent, received, converted to python, serialized again, sent to the client, deserialized to javascript/python/skulpt…

If this is not the case, then I will repeat what @divyeshlakhotia and @p.colbert already said: please ask the question providing more details about what you do, what you get and what you want to get instead.

See here: How to ask a good question

12

This always returns None. You call the function return_ordered, but you don’t return its value, e.g. return return_ordered(data).

Not saying that’s going to make anything else work, but that’s definitely an issue.

13

I’ve decided to use list of dicts instead of a dict, this way the returned data order is preserved.

        #data[row["Food"]] = row[column]
        data.append({row["Food"]: row[column]})