Method: Returns a comma separated list of the field names prepared to be used for a selection after a join with `default_results`.

Method: Fills ORDER BY clause of SQL request based on user supplied parameters.

Method: Fills FROM and WHERE clauses of SQL request for ‘Intervals’ section of data response based on user supplied parameters.

Method: Get join and where clauses for refunds based on user supplied parameters.

Method: Updates start and end dates for intervals so that they represent intervals’ borders, not times when data in db were recorded.

Method: Change structure of intervals to form a correct response.

Method: Fills in interval gaps from DB with 0-filled objects.

Method: Converts input datetime parameters to local timezone. If there are no inputs from the user in query_args, uses default from $defaults.

Method: Removes extra records from intervals so that only requested number of records get returned.

Method: Returns expected number of items on the page in case of date ordering.