MongoQueryableGroupByTSource, TKey, TResult Method (IMongoQueryableTSource, ExpressionFuncTSource, TKey, ExpressionFuncTKey, IEnumerableTSource, TResult) |
Groups the elements of a sequence according to a specified key selector function
and creates a result value from each group and its key.
Namespace:
MongoDB.Driver.Linq
Assembly:
MongoDB.Driver (in MongoDB.Driver.dll) Version: 2.16.0+eeafbea0921243a5868b81984e1083a07c1f75bc
Syntax public static IMongoQueryable<TResult> GroupBy<TSource, TKey, TResult>(
this IMongoQueryable<TSource> source,
Expression<Func<TSource, TKey>> keySelector,
Expression<Func<TKey, IEnumerable<TSource>, TResult>> resultSelector
)
<ExtensionAttribute>
Public Shared Function GroupBy(Of TSource, TKey, TResult) (
source As IMongoQueryable(Of TSource),
keySelector As Expression(Of Func(Of TSource, TKey)),
resultSelector As Expression(Of Func(Of TKey, IEnumerable(Of TSource), TResult))
) As IMongoQueryable(Of TResult)
[<ExtensionAttribute>]
static member GroupBy :
source : IMongoQueryable<'TSource> *
keySelector : Expression<Func<'TSource, 'TKey>> *
resultSelector : Expression<Func<'TKey, IEnumerable<'TSource>, 'TResult>> -> IMongoQueryable<'TResult>
Parameters
- source
- Type: MongoDB.Driver.LinqIMongoQueryableTSource
An IMongoQueryableT whose elements to group. - keySelector
- Type: System.Linq.ExpressionsExpressionFuncTSource, TKey
A function to extract the key for each element. - resultSelector
- Type: System.Linq.ExpressionsExpressionFuncTKey, IEnumerableTSource, TResult
A function to create a result value from each group.
Type Parameters
- TSource
- The type of the elements of source.
- TKey
- The type of the key returned by the function represented in keySelector.
- TResult
- The type of the result value returned by resultSelector.
Return Value
Type:
IMongoQueryableTResult
An
IMongoQueryableT that has a type argument of TResult and where
each element represents a projection over a group and its key.
Usage Note
In Visual Basic and C#, you can call this method as an instance method on any object of type
IMongoQueryableTSource. When you use instance method syntax to call this method, omit the first parameter. For more information, see
Extension Methods (Visual Basic) or
Extension Methods (C# Programming Guide).
See Also