IFulltextQueryTDocumentGroupByTKey(ExpressionFuncTDocument, TKey, Int32) Method

Group the results of this query by the given key and return a given amount of results per group. Supported with Sphinx 2.2.1 and above.

Definition

Namespace: SphinxConnector.FluentApi
Assembly: SphinxConnector (in SphinxConnector.dll) Version: 6.1.0

C#

IFulltextQuery<TDocument> GroupBy<TKey>(
	Expression<Func<TDocument, TKey>> keySelector,
	int maxResultsPerGroup
)

VB

Function GroupBy(Of TKey) ( 
	keySelector As Expression(Of Func(Of TDocument, TKey)),
	maxResultsPerGroup As Integer
) As IFulltextQuery(Of TDocument)

Parameters

keySelector ExpressionFuncTDocument, TKey: A function to extract the key from a document.
maxResultsPerGroup Int32: The (maximum) number of results to return per group.

Type Parameters

TKey: The type of the key returned by the function that is represented by keySelector.

Return Value

IFulltextQueryTDocument
The current instance.

Example

C#

using (IFulltextSession fulltextSession = fulltextStore.StartSession())
{
    var results = fulltextSession.Query<Product>().
                                  Match("a product").
                                  GroupBy(p => p.CategoryId, 5).
                                  Select(p => new
                                  {
                                      p.CategoryId,
                                      p.Name,
                                      p.Price                                               
                                  }).ToList();
 }

Exceptions

ArgumentNullException	Occurs when keySelector is null.
ArgumentOutOfRangeException	Occurs when maxResultsPerGroup is less than one.
InvalidOperationException	Occurs when this method called more than once for query.