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Querying: Filtering Time Series


  • Time series entries can be filtered by their value (e.g. to retrieve a "Thermometer" time series entries whose measurement exceeds 32 Celsius degrees) or tag (e.g. to retrieve all the entries whose tag is "Thermometer No. 3").

  • Entries can also be filtered by the contents of a document they refer to.
    A time series entry's tag can contain the ID of a document. A query can load the document that the entry refers to, check its properties and filter time series entries by them.

  • In this page:


Filtering

In an RQL query, use the where keyword to filter time series entries by their tags or values.

  • Filter entries by tag using where Tag.
    E.g. -

    • from Users as u where Age < 30
      select timeseries(
          from HeartRate 
             between '2020-05-27T00:00:00.0000000Z' 
                  and '2020-06-23T00:00:00.0000000Z'
             // Where this is the tag
             where Tag == 'watches/fitbit'
      )
    • from Users as u where Age < 30
      select timeseries(
          from HeartRate 
             between '2020-05-27T00:00:00.0000000Z' 
                  and '2020-06-23T00:00:00.0000000Z'
             // Where the tag is one of several options
             where Tag in ('watches/Letsfit', 'watches/Willful', 'watches/Lintelek')
      )
  • Filter entries by value using where Value.
    E.g. -

    from Users as u where Age < 30
    select timeseries(
        from HeartRate 
           between '2020-05-27T00:00:00.0000000Z' 
                and '2020-06-23T00:00:00.0000000Z'
           where Value < 80
    )

Using Tags as References - load tag

Use the load Tag expression to load a document whose ID is stored in a time series entry's tag.
Use load Tag with where to filter your results by properties of the loaded document, as we do in the following example.

from Companies as Company where Company.Address.Country = "USA"
select timeseries(
    from StockPrice
       load Tag as Broker
       where Broker.Title == "Sales Representative"
    )
  • load Tag as Broker
    Load the document each entry's tag refers to.
    Here, we load profiles of potential stock brokers.
  • where Broker.Title == "Sales Representative"
    Filter time series entries so we remain with those referring to sales representatives.

Client Usage Samples

You can run queries from your client using raw RQL and LINQ.

  • Learn how to run a LINQ time series query here.
  • Learn how to run a raw RQL time series query here.

To filter results, use Where() in a LINQ query or where in a raw RQL query.
To filter results by a tag reference to a document, use LoadByTag() in a LINQ query or load tag in a raw RQL query.

  • In this sample, we send the query we presented above to the server in raw RQL and in LINQ format.

    IRavenQueryable<TimeSeriesRawResult> query =
        (IRavenQueryable<TimeSeriesRawResult>)session.Query<Company>()
    
            // Choose user profiles of users under the age of 30
            .Where(c => c.Address.Country == "USA")
            .Select(q => RavenQuery.TimeSeries(q, "StockPrice")
    
            .LoadByTag<Employee>()
            .Where((ts, src) => src.Title == "Sales Representative")
    
            .ToList());
    
    var result = query.ToList();
    // Raw query with no aggregation - Select syntax
    IRawDocumentQuery<TimeSeriesRawResult> nonAggregatedRawQuery =
        session.Advanced.RawQuery<TimeSeriesRawResult>(@"
            from Companies as c where c.Address.Country = 'USA'
            select timeseries(
                from StockPrice
                   load Tag as emp
                   where emp.Title == 'Sales Representative'
            )");
    
    var nonAggregatedRawQueryResult = nonAggregatedRawQuery.ToList();