With PostgreSQL I can use the generate_series
feature to generate a list of days between two dates, and with a little effort, even generate a list of sales made by day within that range, even if there are no sales for the day, displaying the day with a value of 0.
Example:
SELECT t.day::date,
(SELECT COUNT(1) FROM sales WHERE sales.date = t.day::date) AS sales_at_day
FROM generate_series(timestamp '2021-03-07'
, timestamp '2021-08-16'
, interval '1 day') AS t(day);
I now have a report in Elasticsearch for the same purpose, showing sales by days within a range. I am trying to display days in results that have no sales, but this days is not displayed.
For example, if my filter is for the day 2021-03-01 / 2021-10-01, and sales will only occur between 2021-04-02 and 2021-09-01, the dates between 2021-03-01 and 2021-04 -01 do not display dates with zero values.
{
"query": {
"range": {
"date": {
"from": "2020-03-01T00:00:00+0300",
"to": "2021-10-01T00:00:00+0300",
"include_lower": true,
"include_upper": true,
"boost": 1.0
}
}
},
"aggs" : {
"sales_over_time" : {
"date_histogram" : {
"field" : "date",
"interval" : "day",
"min_doc_count": 0
}
}
}
}
Does Elasticsearch support this feature, or do I have to find a way to fill the result with non-existing dates?