Queryable.Join Method

Definition

Correlaciona os elementos de duas sequências com base em chaves de correspondência.Correlates the elements of two sequences based on matching keys.

Overloads

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

Correlaciona os elementos de duas sequências com base em chaves de correspondência.Correlates the elements of two sequences based on matching keys. O comparador de igualdade padrão é usado para comparar chaves.The default equality comparer is used to compare keys.

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

Correlaciona os elementos de duas sequências com base em chaves de correspondência.Correlates the elements of two sequences based on matching keys. Um IEqualityComparer<T> especificado é usado para comparar chaves.A specified IEqualityComparer<T> is used to compare keys.

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

Correlaciona os elementos de duas sequências com base em chaves de correspondência.Correlates the elements of two sequences based on matching keys. 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> ^ Join(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, TInner, TResult> ^> ^ resultSelector);
public static System.Linq.IQueryable<TResult> Join<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,TInner,TResult>> resultSelector);
static member Join : 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, 'Inner, 'Result>> -> System.Linq.IQueryable<'Result>
<Extension()>
Public Function Join(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, 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,TInner,TResult>>

Uma função para criar um elemento de resultado de dois elementos correspondentes.A function to create a result element from two matching elements.

Returns

IQueryable<TResult>

Um IQueryable<T> com elementos do tipo TResult obtidos pela execução de uma junção interna em duas sequências.An IQueryable<T> that has elements of type TResult obtained by performing an inner 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 Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,TInner,TResult>>) para executar uma junção interna de duas sequências com base em uma chave comum.The following code example demonstrates how to use Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,TInner,TResult>>) to perform an inner join of two sequences based on a common key.

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

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

public static void JoinEx1()
{
    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 };

    // Join the list of Person objects and the list of Pet objects
    // to create a list of person-pet pairs where each element is
    // an anonymous type that contains the name of pet and the name
    // of the person that owns the pet.
    var query = people.AsQueryable().Join(pets,
                    person => person,
                    pet => pet.Owner,
                    (person, pet) =>
                        new { OwnerName = person.Name, Pet = pet.Name });

    foreach (var obj in query)
    {
        Console.WriteLine(
            "{0} - {1}",
            obj.OwnerName,
            obj.Pet);
    }
}

/*
    This code produces the following output:

    Hedlund, Magnus - Daisy
    Adams, Terry - Barley
    Adams, Terry - 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 JoinEx1()
    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})

    ' Join the list of Person objects and the list of Pet objects 
    ' to create a list of person-pet pairs where each element is 
    ' an anonymous type that contains pet's name and the name of the
    ' Person object that owns the pet.
    Dim query = people.AsQueryable().Join(pets, _
                    Function(person) person, _
                    Function(pet) pet.Owner, _
                    Function(person, pet) _
                        New With {.OwnerName = person.Name, .Pet = pet.Name})

    Dim output As New System.Text.StringBuilder
    For Each obj In query
        output.AppendLine(String.Format( _
            "{0} - {1}", obj.OwnerName, obj.Pet))
    Next

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

' This code produces the following output:

' Hedlund, Magnus - Daisy
' Adams, Terry - Barley
' Adams, Terry - 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 Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,TInner,TResult>>) gera um MethodCallExpression que representa a chamada Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,TInner,TResult>>) si mesmo como um método genérico construído.The Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,TInner,TResult>>) method generates a MethodCallExpression that represents calling Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,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 Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,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 Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,TInner,TResult>>) depends on the implementation of the type of the outer parameter. O comportamento esperado é o de uma junção interna.The expected behavior is that of an inner join. As funções outerKeySelector e innerKeySelector são usadas para extrair chaves de outer e inner, respectivamente.The outerKeySelector and innerKeySelector functions are used to extract keys from outer and inner, respectively. Essas chaves são comparadas com a igualdade para corresponder elementos de cada sequência.These keys are compared for equality to match elements from each sequence. Um par de elementos é armazenado para cada elemento em inner que corresponde a um elemento no outer.A pair of elements is stored for each element in inner that matches an element in outer. Em seguida, a função resultSelector é invocada para projetar um objeto de resultado de cada par de elementos correspondentes.Then the resultSelector function is invoked to project a result object from each pair of matching elements.

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

Correlaciona os elementos de duas sequências com base em chaves de correspondência.Correlates the elements of two sequences based on matching keys. 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> ^ Join(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, TInner, TResult> ^> ^ resultSelector, System::Collections::Generic::IEqualityComparer<TKey> ^ comparer);
public static System.Linq.IQueryable<TResult> Join<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,TInner,TResult>> resultSelector, System.Collections.Generic.IEqualityComparer<TKey> comparer);
static member Join : 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, 'Inner, 'Result>> * System.Collections.Generic.IEqualityComparer<'Key> -> System.Linq.IQueryable<'Result>
<Extension()>
Public Function Join(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, 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,TInner,TResult>>

Uma função para criar um elemento de resultado de dois elementos correspondentes.A function to create a result element from two matching elements.

comparer
IEqualityComparer<TKey>

Um IEqualityComparer<T> para executar hash e comparar chaves.An IEqualityComparer<T> to hash and compare keys.

Returns

IQueryable<TResult>

Um IQueryable<T> com elementos do tipo TResult obtidos pela execução de uma junção interna em duas sequências.An IQueryable<T> that has elements of type TResult obtained by performing an inner 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 Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,TInner,TResult>>, IEqualityComparer<TKey>) gera um MethodCallExpression que representa a chamada Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,TInner,TResult>>, IEqualityComparer<TKey>) si mesmo como um método genérico construído.The Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,TInner,TResult>>, IEqualityComparer<TKey>) method generates a MethodCallExpression that represents calling Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,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 Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,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 Join<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,TInner,TResult>>, IEqualityComparer<TKey>) depends on the implementation of the type of the outer parameter. O comportamento esperado é o de uma junção interna.The expected behavior is that of an inner join. As funções outerKeySelector e innerKeySelector são usadas para extrair chaves de outer e inner, respectivamente.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 criar um par correspondente para cada elemento em inner que corresponde a um elemento em outer.The outcome of the comparisons is used to create a matching pair for each element in inner that matches an element in outer. Em seguida, a função resultSelector é invocada para projetar um objeto de resultado de cada par de elementos correspondentes.Then the resultSelector function is invoked to project a result object from each pair of matching elements.

Applies to