[Fixed]-Django: Making an efficient query by removing 340 duplicate queries

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Rather than performing a query per day, you can retrieve all objects ordered by date and then use itertools.groupby() to split them into dates.

def data_points(self):
    trades = self.get_queryset()
    data_x = []
    data_y = []

    for date, subset in itertools.groupby(trades, lambda t: t.date):
        average_price = average(subset) # average() needs to be implemented
        if average_price > 0:
            data_x.append(date.strftime('%Y-%m-%d'))
            data_y.append(average_price)
    return data_x, data_y

This approach trades web server CPU for DB CPU/IO, this may or may not be the best approach depending on your infrastructure

👤Iain Shelvington

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