Count Query Results

• The following options are available to count query results:

  • Count

  • LongCount

  • Get number of results from query stats

Count

• When the number of resulting items is expected to be an Int32 variable,
  use Count in a synchronous session (or CountAsync in an async session).

• Count is implemented in System.Linq.
  CountAsync is implemented in Raven.Client.Documents.

• An OverflowException will be thrown if the number of items exceeds Int32.MaxValue.

• Query
• Query_async
• DocumentQuery
• RQL

// using System.Linq;
// ==================

int numberOfOrders = session
  .Query<Order>()
  .Where(order => order.ShipTo.Country == "UK")
   // Calling 'Count' from System.Linq
  .Count();

// The query returns the NUMBER of orders shipped to UK (Int32)

// using Raven.Client.Documents;
// using Raven.Client.Documents.Linq;
// ==================================

int numberOfOrders = await asyncSession
  .Query<Order>()
   // Calling 'Where' from Raven.Client.Documents.Linq
  .Where(order => order.ShipTo.Country == "UK")
   // Calling 'CountAsync' from Raven.Client.Documents
  .CountAsync();

// The query returns the NUMBER of orders shipped to UK (Int32)

// using Raven.Client.Documents.Session;
// =====================================

int numberOfOrders = session.Advanced
  .DocumentQuery<Order>()
  .WhereEquals(order => order.ShipTo.Country, "UK")
   // Calling 'Count' from Raven.Client.Documents.Session
  .Count();

// The query returns the NUMBER of orders shipped to UK (Int32)

from "Orders"
where ShipTo.Country == "UK" limit 0, 0

// The RQL generated will trigger query execution
// however, no documents are returned (limit is set 0)

LongCount

• When the number of resulting items is expected to be an Int64 variable,
  use LongCount in a synchronous session (or LongCountAsync in an async session).

• LongCount is implemented in both Raven.Client.Documents & System.Linq (use as needed).
  LongCountAsync is implemented in Raven.Client.Documents.

• Query
• Query_async
• DocumentQuery
• RQL

// using Raven.Client.Documents;
// using Raven.Client.Documents.Linq;
// ==================================

long numberOfOrders = session
  .Query<Order>()
   // Calling 'Where' from Raven.Client.Documents.Linq
  .Where(order => order.ShipTo.Country == "UK")
   // Calling 'LongCount' from Raven.Client.Documents
  .LongCount();

// The query returns the NUMBER of orders shipped to UK (Int64)

// using Raven.Client.Documents;
// using Raven.Client.Documents.Linq;
// ==================================

long numberOfOrders = await asyncSession
  .Query<Order>()
   // Calling 'Where' from Raven.Client.Documents.Linq
  .Where(order => order.ShipTo.Country == "UK")
   // Calling 'LongCountAsync' from Raven.Client.Documents
  .LongCountAsync();

// The query returns the NUMBER of orders shipped to UK (Int64)

// using Raven.Client.Documents.Session;
// =====================================

long numberOfOrders = session.Advanced
  .DocumentQuery<Order>()
  .WhereEquals(order => order.ShipTo.Country, "UK")
   // Calling 'LongCount' from  Raven.Client.Documents.Session
  .LongCount();

// The query returns the NUMBER of orders shipped to UK (Int64)

from "Orders"
where ShipTo.Country == "UK" limit 0, 0

// The RQL generated will trigger query execution
// however, no documents are returned (limit is set 0)

Get count from query stats

• When executing a query, you can retrieve the query statistics, which include the total number of results.

• The total number of results is available in the TotalResults property of the QueryStatistics object.
  Learn more in Get Query Statistics.