Skip to main content

Choosing Time Series Range

Choose range in a query​

Specify range:​

  • Provide 'from' & 'to' DateTime values to the time series query to retrieve entries only from that range (inclusive).
    Omitting these parameters will retrieve the entire series.

  • The provided DateTime values are handled by the server as UTC.
    The client does Not perform any conversion to UTC prior to sending the request to the server.

  • In this example, we specify a 10-minute range from which we retrieve UK employees "HeartRates" entries.

var baseTime = new DateTime(2020, 5, 17, 00, 00, 00);
var from = baseTime;
var to = baseTime.AddMinutes(10);

var query = session
  .Query<Employee>()
  .Where(employee => employee.Address.Country == "UK")
  .Select(employee => RavenQuery
       // Specify the range:
       // pass a 'from' and a 'to' DateTime values to the 'TimeSeries' method
      .TimeSeries(employee, "HeartRates", from, to)
       // Call 'Offset' to adjust the timestamps in the returned results to your local time (optional)
      .Offset(TimeSpan.FromHours(3))
      .ToList());

// Execute the query
List<TimeSeriesRawResult> result = query.ToList();

Retrieve first or last entries:​

  • Use FromFirst() to specify the time frame from the start of the time series.
    Use FromLast() to specify the time frame from the end of the time series.
    A query function can use either FromFirst or FromLast, but not both.

  • In this example, we select only entries in the last 30 minutes of the "HeartRates" time series.

var query = session
  .Query<Employee>()
  .Select(p => RavenQuery
      .TimeSeries(p, "HeartRates")
       // Call 'FromLast'
       // specify the time frame from the end of the time series
      .FromLast(x => x.Minutes(30))
      .Offset(TimeSpan.FromHours(3))
      .ToList());

// Execute the query
List<TimeSeriesRawResult> result = query.ToList();

Choose range - RQL syntax​

between and and:​

  • Use the between and and keywords to retrieve time series entries from the specified range (inclusive).
    Provide the timestamps in UTC format. E.g.:
from "Employees"
where Address.Country == "UK"
select timeseries(
  from HeartRates
  between "2020-05-17T00:00:00.0000000Z" // start of range
  and "2020-05-17T01:00:00.0000000Z"     // end of range
)

// Results will include only time series entries within the specified range for employees from UK.
  • RQL queries can be executed from Studio's query view.
    Using Studio, you can apply parameters as follows for a clearer query.
$from = "2020-05-17T00:00:00.0000000Z"
$to = "2020-05-17T01:00:00.0000000Z"

from "Employees"
where Address.Country == "UK"
select timeseries(
  from HeartRates
  between $from and $to  // using parameters
)

first and last:​

  • Use first to specify the time frame from the start of the time series.
    Use last to specify the time frame from the end of the time series.
    A query function can use either first or last, but not both. E.g. -
// Retrieve all entries from the last day, starting from the end of time series "HeartRates"
from "Employees"
select timeseries(
  from HeartRates
  last 1 day
)
// Retrieve the first 10 minutes of entries from the beginning of time series "HeartRates"
from "Employees"
select timeseries(
  from HeartRates
  first 10 min
)

  • The range is specified using a whole number of one of the following units.

    • seconds ( seconds/ second / s )
    • minutes ( minutes / minute / min )
    • hours ( hours / hour / h )
    • days ( days / day / d )
    • months ( months / month / mon / mo )
    • quarters ( quarters / quarter / q )
    • years ( years / year / y )
    • Note: milliseconds are currently not supported by 'first' and 'last' in a time series query.