Session: Appending & Updating Time Series

• Creating a Time Series
  Append an entry to a time series that doesn't exist yet,
  to create the time series and add it the new entry.
• Creating a Time Series Entry
  Append an existing time series a new entry,
  to add the entry to this series at the specified timestamp.
• Modifying Entry Values
  Append a time series an entry it already has,
  to update the existing entry with the new data.

There are two TimeSeriesFor.Append methods:

• Append an entry with a single value.
  

  // Append an entry with a single value (double)
  void Append(DateTime timestamp, double value, string tag = null);

• Append an entry with multiple values.
  

  // Append an entry with multiple values (IEnumerable)
  void Append(DateTime timestamp, IEnumerable<double> values, string tag = null);

Parameters

Exceptions
If the document doesn't exist, a DocumentDoesNotExistException exception is thrown.

• Either pass TimeSeriesFor an explicit document ID,
  -or-
  Pass it an entity tracked by the session, e.g. a document object returned from session.Query or from session.Load.
• Pass TimeSeriesFor the time series name.

In this sample, we append an entry with a single value.
Though We run a loop to append multiple entries, all entries are appended in a single transaction when SaveChanges is executed.

var baseline = DateTime.Today;

// Append 10 heart rate values
using (var session = store.OpenSession())
{
    session.Store(new User { Name = "John" }, "users/john");

    ISessionDocumentTimeSeries tsf = session.TimeSeriesFor("users/john", "HeartRates");

    for (int i = 0; i < 10; i++)
    {
        tsf.Append(baseline.AddSeconds(i), new[] { 67d }, "watches/fitbit");
    }

    session.SaveChanges();
}

Here, we append multi-value StockPrice entries.
Notice the clarity gained by naming the values.

using (var session = store.OpenSession())
{
    session.Store(new User { Name = "John" }, "users/john");

    session.TimeSeriesFor("users/john", "StockPrices")
    .Append(baseline.AddDays(1),
        new[] { 52, 54, 63.5, 51.4, 9824 }, "companies/kitchenAppliances");

    session.TimeSeriesFor("users/john", "StockPrices")
    .Append(baseline.AddDays(2),
        new[] { 54, 55, 61.5, 49.4, 8400 }, "companies/kitchenAppliances");

    session.TimeSeriesFor("users/john", "StockPrices")
    .Append(baseline.AddDays(3),
        new[] { 55, 57, 65.5, 50, 9020 }, "companies/kitchenAppliances");

    session.SaveChanges();
}

using (var session = store.OpenSession())
{
    session.Store(new User { Name = "John" }, "users/john");

    session.TimeSeriesFor<StockPrice>("users/john")
    .Append(baseline.AddDays(1), new StockPrice
    {
        Open = 52,
        Close = 54,
        High = 63.5,
        Low = 51.4,
        Volume = 9824,
    }, "companies/kitchenAppliances");

    session.TimeSeriesFor<StockPrice>("users/john")
    .Append(baseline.AddDays(2), new StockPrice
    {
        Open = 54,
        Close = 55,
        High = 61.5,
        Low = 49.4,
        Volume = 8400,
    }, "companies/kitchenAppliances");

    session.TimeSeriesFor<StockPrice>("users/john")
    .Append(baseline.AddDays(3), new StockPrice
    {
        Open = 55,
        Close = 57,
        High = 65.5,
        Low = 50,
        Volume = 9020,
    }, "companies/kitchenAppliances");

    session.SaveChanges();
}