MongoQueryable.GroupBy<TSource, TKey, TResult> Method (IMongoQueryable<TSource>, Expression<Func<TSource, TKey>>, Expression<Func<TKey, IEnumerable<TSource>, 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: 2.6.0+Branch.origin/v2.6.x.Sha.593796a7b35dc59243383bcc684de296a5468f2e
Syntaxpublic 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.Linq.IMongoQueryable<TSource>
An IMongoQueryable< T> whose elements to group. - keySelector
- Type: System.Linq.Expressions.Expression<Func<TSource, TKey>>
A function to extract the key for each element. - resultSelector
- Type: System.Linq.Expressions.Expression<Func<TKey, IEnumerable<TSource>, 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:
IMongoQueryable<TResult>
An
IMongoQueryable< T> 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
IMongoQueryable<TSource>. 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