Queryable.GroupJoin Método

Definición

Establece una correlación entre los elementos de dos secuencias basándose en la igualdad de clave y agrupa los resultados.Correlates the elements of two sequences based on key equality and groups the results.

Sobrecargas

GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>)

Establece una correlación entre los elementos de dos secuencias basándose en la igualdad de clave y agrupa los resultados.Correlates the elements of two sequences based on key equality and groups the results. El comparador de igualdad predeterminado se usa para comparar claves.The default equality comparer is used to compare keys.

GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>, IEqualityComparer<TKey>)

Establece una correlación entre los elementos de dos secuencias basándose en la igualdad de clave y agrupa los resultados.Correlates the elements of two sequences based on key equality and groups the results. Se usa un IEqualityComparer<T> especificado para comparar claves.A specified IEqualityComparer<T> is used to compare keys.

GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>)

Establece una correlación entre los elementos de dos secuencias basándose en la igualdad de clave y agrupa los resultados.Correlates the elements of two sequences based on key equality and groups the results. El comparador de igualdad predeterminado se usa para comparar claves.The default equality comparer is used to compare keys.

public:
generic <typename TOuter, typename TInner, typename TKey, typename TResult>
[System::Runtime::CompilerServices::Extension]
 static System::Linq::IQueryable<TResult> ^ GroupJoin(System::Linq::IQueryable<TOuter> ^ outer, System::Collections::Generic::IEnumerable<TInner> ^ inner, System::Linq::Expressions::Expression<Func<TOuter, TKey> ^> ^ outerKeySelector, System::Linq::Expressions::Expression<Func<TInner, TKey> ^> ^ innerKeySelector, System::Linq::Expressions::Expression<Func<TOuter, System::Collections::Generic::IEnumerable<TInner> ^, TResult> ^> ^ resultSelector);
public static System.Linq.IQueryable<TResult> GroupJoin<TOuter,TInner,TKey,TResult> (this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<Func<TOuter,TKey>> outerKeySelector, System.Linq.Expressions.Expression<Func<TInner,TKey>> innerKeySelector, System.Linq.Expressions.Expression<Func<TOuter,System.Collections.Generic.IEnumerable<TInner>,TResult>> resultSelector);
static member GroupJoin : System.Linq.IQueryable<'Outer> * seq<'Inner> * System.Linq.Expressions.Expression<Func<'Outer, 'Key>> * System.Linq.Expressions.Expression<Func<'Inner, 'Key>> * System.Linq.Expressions.Expression<Func<'Outer, seq<'Inner>, 'Result>> -> System.Linq.IQueryable<'Result>
<Extension()>
Public Function GroupJoin(Of TOuter, TInner, TKey, TResult) (outer As IQueryable(Of TOuter), inner As IEnumerable(Of TInner), outerKeySelector As Expression(Of Func(Of TOuter, TKey)), innerKeySelector As Expression(Of Func(Of TInner, TKey)), resultSelector As Expression(Of Func(Of TOuter, IEnumerable(Of TInner), TResult))) As IQueryable(Of TResult)

Parámetros de tipo

TOuter

Tipo de los elementos de la primera secuencia.The type of the elements of the first sequence.

TInner

Tipo de los elementos de la segunda secuencia.The type of the elements of the second sequence.

TKey

Tipo de las claves devueltas por las funciones del selector de claves.The type of the keys returned by the key selector functions.

TResult

Tipo de los elementos del resultado.The type of the result elements.

Parámetros

outer
IQueryable<TOuter>

Primera secuencia que se va a combinar.The first sequence to join.

inner
IEnumerable<TInner>

Secuencia que se va a combinar con la primera secuencia.The sequence to join to the first sequence.

outerKeySelector
Expression<Func<TOuter,TKey>>

Función para extraer la clave de combinación a partir de cada elemento de la primera secuencia.A function to extract the join key from each element of the first sequence.

innerKeySelector
Expression<Func<TInner,TKey>>

Función para extraer la clave de combinación a partir de cada elemento de la segunda secuencia.A function to extract the join key from each element of the second sequence.

resultSelector
Expression<Func<TOuter,IEnumerable<TInner>,TResult>>

Función para crear un elemento de resultado a partir de un elemento de la primera secuencia y una colección de elementos coincidentes de la segunda.A function to create a result element from an element from the first sequence and a collection of matching elements from the second sequence.

Devoluciones

IQueryable<TResult>

IQueryable<T> que contiene elementos de tipo TResult que se han obtenido al realizar una combinación agrupada de dos secuencias.An IQueryable<T> that contains elements of type TResult obtained by performing a grouped join on two sequences.

Excepciones

outer o inner o outerKeySelector o innerKeySelector o resultSelector es null.outer or inner or outerKeySelector or innerKeySelector or resultSelector is null.

Ejemplos

En el ejemplo de código siguiente se muestra cómo utilizar GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>) para realizar una combinación agrupada en dos secuencias.The following code example demonstrates how to use GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>) to perform a grouped join on two sequences.

class Person
{
    public string Name { get; set; }
}

class Pet
{
    public string Name { get; set; }
    public Person Owner { get; set; }
}

public static void GroupJoinEx1()
{
    Person magnus = new Person { Name = "Hedlund, Magnus" };
    Person terry = new Person { Name = "Adams, Terry" };
    Person charlotte = new Person { Name = "Weiss, Charlotte" };

    Pet barley = new Pet { Name = "Barley", Owner = terry };
    Pet boots = new Pet { Name = "Boots", Owner = terry };
    Pet whiskers = new Pet { Name = "Whiskers", Owner = charlotte };
    Pet daisy = new Pet { Name = "Daisy", Owner = magnus };

    List<Person> people = new List<Person> { magnus, terry, charlotte };
    List<Pet> pets = new List<Pet> { barley, boots, whiskers, daisy };

    // Create a list where each element is an anonymous 
    // type that contains a person's name and a collection 
    // of names of the pets that are owned by them.
    var query =
        people.AsQueryable().GroupJoin(pets,
                         person => person,
                         pet => pet.Owner,
                         (person, petCollection) =>
                             new
                             {
                                 OwnerName = person.Name,
                                 Pets = petCollection.Select(pet => pet.Name)
                             });

    foreach (var obj in query)
    {
        // Output the owner's name.
        Console.WriteLine("{0}:", obj.OwnerName);
        // Output each of the owner's pet's names.
        foreach (string pet in obj.Pets)
            Console.WriteLine("  {0}", pet);
    }
}

/*
    This code produces the following output:

    Hedlund, Magnus:
      Daisy
    Adams, Terry:
      Barley
      Boots
    Weiss, Charlotte:
      Whiskers
*/

Structure Person
    Public Name As String
End Structure

Structure Pet
    Public Name As String
    Public Owner As Person
End Structure

Shared Sub GroupJoinEx1()
    Dim magnus As New Person With {.Name = "Hedlund, Magnus"}
    Dim terry As New Person With {.Name = "Adams, Terry"}
    Dim charlotte As New Person With {.Name = "Weiss, Charlotte"}

    Dim barley As New Pet With {.Name = "Barley", .Owner = terry}
    Dim boots As New Pet With {.Name = "Boots", .Owner = terry}
    Dim whiskers As New Pet With {.Name = "Whiskers", .Owner = charlotte}
    Dim daisy As New Pet With {.Name = "Daisy", .Owner = magnus}

    Dim people As New List(Of Person)(New Person() {magnus, terry, charlotte})
    Dim pets As New List(Of Pet)(New Pet() {barley, boots, whiskers, daisy})

    ' Create a list where each element is an anonymous 
    ' type that contains a person's name and a collection
    ' of the names of the pets that are owned by them.
    Dim query = _
        people.AsQueryable().GroupJoin(pets, _
                   Function(person) person, _
                   Function(pet) pet.Owner, _
                   Function(person, petCollection) _
                       New With {.OwnerName = person.Name, _
                                 .Pets = petCollection.Select( _
                                                    Function(pet) pet.Name)})

    Dim output As New System.Text.StringBuilder
    For Each obj In query
        ' Output the owner's name.
        output.AppendLine(String.Format("{0}:", obj.OwnerName))
        ' Output each of the owner's pet's names.
        For Each pet As String In obj.Pets
            output.AppendLine(String.Format("  {0}", pet))
        Next
    Next

    ' Display the output.
    MsgBox(output.ToString())
End Sub

' This code produces the following output:

' Hedlund, Magnus:
'   Daisy
' Adams, Terry:
'   Barley
'   Boots
' Weiss, Charlotte:
'   Whiskers

Comentarios

Este método tiene al menos un parámetro de tipo Expression<TDelegate> cuyo argumento de tipo es uno de los tipos de Func<T,TResult>.This method has at least one parameter of type Expression<TDelegate> whose type argument is one of the Func<T,TResult> types. Para estos parámetros, puede pasar una expresión lambda y se compilará en un Expression<TDelegate>.For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<TDelegate>.

El método GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>) genera un MethodCallExpression que representa la llamada a GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>) como un método genérico construido.The GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>) method generates a MethodCallExpression that represents calling GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>) itself as a constructed generic method. A continuación, pasa el MethodCallExpression al método CreateQuery<TElement>(Expression) de la IQueryProvider representada por la propiedad Provider del parámetro outer.It then passes the MethodCallExpression to the CreateQuery<TElement>(Expression) method of the IQueryProvider represented by the Provider property of the outer parameter.

El comportamiento de la consulta que se produce como resultado de ejecutar un árbol de expresión que representa la llamada a GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>) depende de la implementación del tipo del parámetro outer.The query behavior that occurs as a result of executing an expression tree that represents calling GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>) depends on the implementation of the type of the outer parameter. El comportamiento esperado es que las funciones outerKeySelector y innerKeySelector se utilicen para extraer claves de outer y inner, respectivamente.The expected behavior is that the outerKeySelector and innerKeySelector functions are used to extract keys from outer and inner, respectively. Estas claves se comparan para determinar si coinciden con cada elemento de outer con cero o más elementos de inner.These keys are compared for equality to match each element in outer with zero or more elements from inner. A continuación, se invoca la función resultSelector para proyectar un objeto de resultado de cada grupo de elementos correlacionados.Then the resultSelector function is invoked to project a result object from each group of correlated elements.

GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>, IEqualityComparer<TKey>)

Establece una correlación entre los elementos de dos secuencias basándose en la igualdad de clave y agrupa los resultados.Correlates the elements of two sequences based on key equality and groups the results. Se usa un IEqualityComparer<T> especificado para comparar claves.A specified IEqualityComparer<T> is used to compare keys.

public:
generic <typename TOuter, typename TInner, typename TKey, typename TResult>
[System::Runtime::CompilerServices::Extension]
 static System::Linq::IQueryable<TResult> ^ GroupJoin(System::Linq::IQueryable<TOuter> ^ outer, System::Collections::Generic::IEnumerable<TInner> ^ inner, System::Linq::Expressions::Expression<Func<TOuter, TKey> ^> ^ outerKeySelector, System::Linq::Expressions::Expression<Func<TInner, TKey> ^> ^ innerKeySelector, System::Linq::Expressions::Expression<Func<TOuter, System::Collections::Generic::IEnumerable<TInner> ^, TResult> ^> ^ resultSelector, System::Collections::Generic::IEqualityComparer<TKey> ^ comparer);
public static System.Linq.IQueryable<TResult> GroupJoin<TOuter,TInner,TKey,TResult> (this System.Linq.IQueryable<TOuter> outer, System.Collections.Generic.IEnumerable<TInner> inner, System.Linq.Expressions.Expression<Func<TOuter,TKey>> outerKeySelector, System.Linq.Expressions.Expression<Func<TInner,TKey>> innerKeySelector, System.Linq.Expressions.Expression<Func<TOuter,System.Collections.Generic.IEnumerable<TInner>,TResult>> resultSelector, System.Collections.Generic.IEqualityComparer<TKey> comparer);
static member GroupJoin : System.Linq.IQueryable<'Outer> * seq<'Inner> * System.Linq.Expressions.Expression<Func<'Outer, 'Key>> * System.Linq.Expressions.Expression<Func<'Inner, 'Key>> * System.Linq.Expressions.Expression<Func<'Outer, seq<'Inner>, 'Result>> * System.Collections.Generic.IEqualityComparer<'Key> -> System.Linq.IQueryable<'Result>
<Extension()>
Public Function GroupJoin(Of TOuter, TInner, TKey, TResult) (outer As IQueryable(Of TOuter), inner As IEnumerable(Of TInner), outerKeySelector As Expression(Of Func(Of TOuter, TKey)), innerKeySelector As Expression(Of Func(Of TInner, TKey)), resultSelector As Expression(Of Func(Of TOuter, IEnumerable(Of TInner), TResult)), comparer As IEqualityComparer(Of TKey)) As IQueryable(Of TResult)

Parámetros de tipo

TOuter

Tipo de los elementos de la primera secuencia.The type of the elements of the first sequence.

TInner

Tipo de los elementos de la segunda secuencia.The type of the elements of the second sequence.

TKey

Tipo de las claves devueltas por las funciones del selector de claves.The type of the keys returned by the key selector functions.

TResult

Tipo de los elementos del resultado.The type of the result elements.

Parámetros

outer
IQueryable<TOuter>

Primera secuencia que se va a combinar.The first sequence to join.

inner
IEnumerable<TInner>

Secuencia que se va a combinar con la primera secuencia.The sequence to join to the first sequence.

outerKeySelector
Expression<Func<TOuter,TKey>>

Función para extraer la clave de combinación a partir de cada elemento de la primera secuencia.A function to extract the join key from each element of the first sequence.

innerKeySelector
Expression<Func<TInner,TKey>>

Función para extraer la clave de combinación a partir de cada elemento de la segunda secuencia.A function to extract the join key from each element of the second sequence.

resultSelector
Expression<Func<TOuter,IEnumerable<TInner>,TResult>>

Función para crear un elemento de resultado a partir de un elemento de la primera secuencia y una colección de elementos coincidentes de la segunda.A function to create a result element from an element from the first sequence and a collection of matching elements from the second sequence.

comparer
IEqualityComparer<TKey>

Comparador que va a aplicar un algoritmo hash y a comparar las claves.A comparer to hash and compare keys.

Devoluciones

IQueryable<TResult>

IQueryable<T> que contiene elementos de tipo TResult que se han obtenido al realizar una combinación agrupada de dos secuencias.An IQueryable<T> that contains elements of type TResult obtained by performing a grouped join on two sequences.

Excepciones

outer o inner o outerKeySelector o innerKeySelector o resultSelector es null.outer or inner or outerKeySelector or innerKeySelector or resultSelector is null.

Comentarios

Este método tiene al menos un parámetro de tipo Expression<TDelegate> cuyo argumento de tipo es uno de los tipos de Func<T,TResult>.This method has at least one parameter of type Expression<TDelegate> whose type argument is one of the Func<T,TResult> types. Para estos parámetros, puede pasar una expresión lambda y se compilará en un Expression<TDelegate>.For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<TDelegate>.

El método GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>, IEqualityComparer<TKey>) genera un MethodCallExpression que representa la llamada a GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>, IEqualityComparer<TKey>) como un método genérico construido.The GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>, IEqualityComparer<TKey>) method generates a MethodCallExpression that represents calling GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>, IEqualityComparer<TKey>) itself as a constructed generic method. A continuación, pasa el MethodCallExpression al método CreateQuery<TElement>(Expression) de la IQueryProvider representada por la propiedad Provider del parámetro outer.It then passes the MethodCallExpression to the CreateQuery<TElement>(Expression) method of the IQueryProvider represented by the Provider property of the outer parameter.

El comportamiento de la consulta que se produce como resultado de ejecutar un árbol de expresión que representa la llamada a GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>, IEqualityComparer<TKey>) depende de la implementación del tipo del parámetro outer.The query behavior that occurs as a result of executing an expression tree that represents calling GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>, IEqualityComparer<TKey>) depends on the implementation of the type of the outer parameter. El comportamiento esperado es que las funciones outerKeySelector y innerKeySelector se utilicen para extraer claves de outer y inner, respectivamente.The expected behavior is that the outerKeySelector and innerKeySelector functions are used to extract keys from outer and inner, respectively. Estas claves se comparan con la igualdad mediante el uso de comparer.These keys are compared for equality by using comparer. El resultado de las comparaciones se usa para hacer coincidir cada elemento de outer con cero o más elementos de inner.The outcome of the comparisons is used to match each element in outer with zero or more elements from inner. A continuación, se invoca la función resultSelector para proyectar un objeto de resultado de cada grupo de elementos correlacionados.Then the resultSelector function is invoked to project a result object from each group of correlated elements.

Se aplica a