Queryable.GroupJoin Method

Definition

Correlaciona os elementos de duas sequências com base na igualdade de chaves e agrupa os resultados.Correlates the elements of two sequences based on key equality and groups the results.

Overloads

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

Correlaciona os elementos de duas sequências com base na igualdade de chaves e agrupa os resultados.Correlates the elements of two sequences based on key equality and groups the results. O comparador de igualdade padrão é usado para comparar chaves.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>)

Correlaciona os elementos de duas sequências com base na igualdade de chaves e agrupa os resultados.Correlates the elements of two sequences based on key equality and groups the results. Um IEqualityComparer<T> especificado é usado para comparar chaves.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>>)

Correlaciona os elementos de duas sequências com base na igualdade de chaves e agrupa os resultados.Correlates the elements of two sequences based on key equality and groups the results. O comparador de igualdade padrão é usado para comparar chaves.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)

Type Parameters

TOuter

O tipo dos elementos da primeira sequência.The type of the elements of the first sequence.

TInner

O tipo dos elementos da segunda sequência.The type of the elements of the second sequence.

TKey

O tipo das chaves retornadas pelas funções de seletor de chave.The type of the keys returned by the key selector functions.

TResult

O tipo dos elementos de resultado.The type of the result elements.

Parameters

outer
IQueryable<TOuter>

A primeira sequência a ser ingressada.The first sequence to join.

inner
IEnumerable<TInner>

A sequência a ser ingressada à primeira sequência.The sequence to join to the first sequence.

outerKeySelector
Expression<Func<TOuter,TKey>>

Uma função para extrair a chave de junção de cada elemento da primeira sequência.A function to extract the join key from each element of the first sequence.

innerKeySelector
Expression<Func<TInner,TKey>>

Uma função para extrair a chave de junção de cada elemento da segunda sequência.A function to extract the join key from each element of the second sequence.

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

Uma função para criar um elemento de resultado de um elemento da primeira sequência e uma coleção de elementos correspondentes da segunda sequência.A function to create a result element from an element from the first sequence and a collection of matching elements from the second sequence.

Returns

IQueryable<TResult>

Um IQueryable<T> que contém elementos do tipo TResult obtidos pela execução de uma junção agrupada em duas sequências.An IQueryable<T> that contains elements of type TResult obtained by performing a grouped join on two sequences.

Exceptions

outer ou inner ou outerKeySelector ou innerKeySelector ou resultSelector é null.outer or inner or outerKeySelector or innerKeySelector or resultSelector is null.

Examples

O exemplo de código a seguir demonstra como usar GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>) para executar uma junção agrupada em duas sequências.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

Remarks

Esse método tem pelo menos um parâmetro do tipo Expression<TDelegate> cujo argumento de tipo é um dos 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 esses parâmetros, você pode passar uma expressão lambda e ela será compilada para um Expression<TDelegate>.For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<TDelegate>.

O método GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>) gera um MethodCallExpression que representa a chamada GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>) si mesmo como um método genérico construído.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. Em seguida, ele passa o MethodCallExpression para o método CreateQuery<TElement>(Expression) do IQueryProvider representado pela propriedade Provider do parâmetro outer.It then passes the MethodCallExpression to the CreateQuery<TElement>(Expression) method of the IQueryProvider represented by the Provider property of the outer parameter.

O comportamento da consulta que ocorre como resultado da execução de uma árvore de expressão que representa a chamada de GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>) depende da implementação do tipo do parâmetro 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. O comportamento esperado é que as funções outerKeySelector e innerKeySelector são usadas para extrair chaves de outer e inner, respectivamente.The expected behavior is that the outerKeySelector and innerKeySelector functions are used to extract keys from outer and inner, respectively. Essas chaves são comparadas de igualdade para corresponder a cada elemento no outer com zero ou mais elementos de inner.These keys are compared for equality to match each element in outer with zero or more elements from inner. Em seguida, a função resultSelector é invocada para projetar um 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>)

Correlaciona os elementos de duas sequências com base na igualdade de chaves e agrupa os resultados.Correlates the elements of two sequences based on key equality and groups the results. Um IEqualityComparer<T> especificado é usado para comparar chaves.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)

Type Parameters

TOuter

O tipo dos elementos da primeira sequência.The type of the elements of the first sequence.

TInner

O tipo dos elementos da segunda sequência.The type of the elements of the second sequence.

TKey

O tipo das chaves retornadas pelas funções de seletor de chave.The type of the keys returned by the key selector functions.

TResult

O tipo dos elementos de resultado.The type of the result elements.

Parameters

outer
IQueryable<TOuter>

A primeira sequência a ser ingressada.The first sequence to join.

inner
IEnumerable<TInner>

A sequência a ser ingressada à primeira sequência.The sequence to join to the first sequence.

outerKeySelector
Expression<Func<TOuter,TKey>>

Uma função para extrair a chave de junção de cada elemento da primeira sequência.A function to extract the join key from each element of the first sequence.

innerKeySelector
Expression<Func<TInner,TKey>>

Uma função para extrair a chave de junção de cada elemento da segunda sequência.A function to extract the join key from each element of the second sequence.

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

Uma função para criar um elemento de resultado de um elemento da primeira sequência e uma coleção de elementos correspondentes da segunda sequência.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>

Um comparador para executar hash e comparar chaves.A comparer to hash and compare keys.

Returns

IQueryable<TResult>

Um IQueryable<T> que contém elementos do tipo TResult obtidos pela execução de uma junção agrupada em duas sequências.An IQueryable<T> that contains elements of type TResult obtained by performing a grouped join on two sequences.

Exceptions

outer ou inner ou outerKeySelector ou innerKeySelector ou resultSelector é null.outer or inner or outerKeySelector or innerKeySelector or resultSelector is null.

Remarks

Esse método tem pelo menos um parâmetro do tipo Expression<TDelegate> cujo argumento de tipo é um dos 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 esses parâmetros, você pode passar uma expressão lambda e ela será compilada para um Expression<TDelegate>.For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<TDelegate>.

O 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>) gera um MethodCallExpression que representa a chamada 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>) si mesmo como um método genérico construído.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. Em seguida, ele passa o MethodCallExpression para o método CreateQuery<TElement>(Expression) do IQueryProvider representado pela propriedade Provider do parâmetro outer.It then passes the MethodCallExpression to the CreateQuery<TElement>(Expression) method of the IQueryProvider represented by the Provider property of the outer parameter.

O comportamento da consulta que ocorre como resultado da execução de uma árvore de expressão que representa a chamada de 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 da implementação do tipo do parâmetro 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. O comportamento esperado é que as funções outerKeySelector e innerKeySelector são usadas para extrair chaves de outer e inner, respectivamente.The expected behavior is that the outerKeySelector and innerKeySelector functions are used to extract keys from outer and inner, respectively. Essas chaves são comparadas por igualdade usando comparer.These keys are compared for equality by using comparer. O resultado das comparações é usado para corresponder a cada elemento em outer com zero ou mais elementos de inner.The outcome of the comparisons is used to match each element in outer with zero or more elements from inner. Em seguida, a função resultSelector é invocada para projetar um 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.

Applies to