Queryable.GroupJoin Method

定義

キーが等しいかどうかに基づいて 2 つのシーケンスの要素を相互に関連付け、その結果をグループ化します。 Correlates the elements of two sequences based on key equality and groups the results.

オーバーロード

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

キーが等しいかどうかに基づいて 2 つのシーケンスの要素を相互に関連付け、その結果をグループ化します。 Correlates the elements of two sequences based on key equality and groups the results. キーの比較には既定の等値比較子が使用されます。 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>)

キーが等しいかどうかに基づいて 2 つのシーケンスの要素を相互に関連付け、その結果をグループ化します。 Correlates the elements of two sequences based on key equality and groups the results. 指定された IEqualityComparer<T> を使用してキーを比較します。 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>>)

キーが等しいかどうかに基づいて 2 つのシーケンスの要素を相互に関連付け、その結果をグループ化します。 Correlates the elements of two sequences based on key equality and groups the results. キーの比較には既定の等値比較子が使用されます。 The default equality comparer is used to compare keys.

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);
型パラメーター
TOuter

最初のシーケンスの要素の型。 The type of the elements of the first sequence.

TInner

2 番目のシーケンスの要素の型。 The type of the elements of the second sequence.

TKey

キー セレクター関数によって返されるキーの型。 The type of the keys returned by the key selector functions.

TResult

結果の要素の型。 The type of the result elements.

パラメーター
outer
IQueryable<TOuter>

結合する最初のシーケンス。 The first sequence to join.

inner
IEnumerable<TInner>

最初のシーケンスに結合するシーケンス。 The sequence to join to the first sequence.

outerKeySelector
Expression<Func<TOuter,TKey>>

最初のシーケンスの各要素から結合キーを抽出する関数。 A function to extract the join key from each element of the first sequence.

innerKeySelector
Expression<Func<TInner,TKey>>

2 番目のシーケンスの各要素から結合キーを抽出する関数。 A function to extract the join key from each element of the second sequence.

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

最初のシーケンスの要素と、2 番目のシーケンスの一致する要素のコレクションから結果の要素を作成する関数。 A function to create a result element from an element from the first sequence and a collection of matching elements from the second sequence.

戻り値
IQueryable<TResult>

2 つのシーケンスに対してグループ化結合を実行して取得した TResult 型の要素が格納されている IQueryable<T> An IQueryable<T> that contains elements of type TResult obtained by performing a grouped join on two sequences.

例外

outerinnerouterKeySelectorinnerKeySelector、または resultSelectornull です。 outer or inner or outerKeySelector or innerKeySelector or resultSelector is null.

次のコード例は、使用する方法を示しますGroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>)2 つのシーケンスに対してグループ化結合を実行します。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

注釈

このメソッドは、少なくとも 1 つのパラメーター型のExpression<TDelegate>型引数は、のいずれか、Func<T,TResult>型。This method has at least one parameter of type Expression<TDelegate> whose type argument is one of the Func<T,TResult> types. ラムダ式で、これらのパラメーターを渡すことができますにコンパイルされると、Expression<TDelegate>します。For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<TDelegate>.

GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>)メソッドを生成、MethodCallExpression呼び出しを表すGroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>)として構築されたジェネリック メソッド自体。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. これは、後、渡します、MethodCallExpressionCreateQuery<TElement>(Expression)のメソッド、IQueryProviderによって表される、Providerのプロパティ、outerパラメーター。It then passes the MethodCallExpression to the CreateQuery<TElement>(Expression) method of the IQueryProvider represented by the Provider property of the outer parameter.

呼び出し元を表す式ツリーを実行した結果として発生するクエリの動作GroupJoin<TOuter,TInner,TKey,TResult>(IQueryable<TOuter>, IEnumerable<TInner>, Expression<Func<TOuter,TKey>>, Expression<Func<TInner,TKey>>, Expression<Func<TOuter,IEnumerable<TInner>,TResult>>)の型の実装によって異なります、outerパラメーター。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. 想定される動作は、outerKeySelectorinnerKeySelector関数を使用してからキーを抽出outerinner、それぞれします。The expected behavior is that the outerKeySelector and innerKeySelector functions are used to extract keys from outer and inner, respectively. これらのキー内の各要素に一致するように等しいかどうか比較outerから 0 個以上の要素を持つinnerします。These keys are compared for equality to match each element in outer with zero or more elements from inner. 次に、resultSelector相関関係を持つ要素の各グループからの結果オブジェクトを射影する関数が呼び出されます。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>)

キーが等しいかどうかに基づいて 2 つのシーケンスの要素を相互に関連付け、その結果をグループ化します。 Correlates the elements of two sequences based on key equality and groups the results. 指定された IEqualityComparer<T> を使用してキーを比較します。 A specified IEqualityComparer<T> is used to compare keys.

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);
型パラメーター
TOuter

最初のシーケンスの要素の型。 The type of the elements of the first sequence.

TInner

2 番目のシーケンスの要素の型。 The type of the elements of the second sequence.

TKey

キー セレクター関数によって返されるキーの型。 The type of the keys returned by the key selector functions.

TResult

結果の要素の型。 The type of the result elements.

パラメーター
outer
IQueryable<TOuter>

結合する最初のシーケンス。 The first sequence to join.

inner
IEnumerable<TInner>

最初のシーケンスに結合するシーケンス。 The sequence to join to the first sequence.

outerKeySelector
Expression<Func<TOuter,TKey>>

最初のシーケンスの各要素から結合キーを抽出する関数。 A function to extract the join key from each element of the first sequence.

innerKeySelector
Expression<Func<TInner,TKey>>

2 番目のシーケンスの各要素から結合キーを抽出する関数。 A function to extract the join key from each element of the second sequence.

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

最初のシーケンスの要素と、2 番目のシーケンスの一致する要素のコレクションから結果の要素を作成する関数。 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>

キーをハッシュして比較する比較子。 A comparer to hash and compare keys.

戻り値
IQueryable<TResult>

2 つのシーケンスに対してグループ化結合を実行して取得した TResult 型の要素が格納されている IQueryable<T> An IQueryable<T> that contains elements of type TResult obtained by performing a grouped join on two sequences.

例外

outerinnerouterKeySelectorinnerKeySelector、または resultSelectornull です。 outer or inner or outerKeySelector or innerKeySelector or resultSelector is null.

注釈

このメソッドは、少なくとも 1 つのパラメーター型のExpression<TDelegate>型引数は、のいずれか、Func<T,TResult>型。This method has at least one parameter of type Expression<TDelegate> whose type argument is one of the Func<T,TResult> types. ラムダ式で、これらのパラメーターを渡すことができますにコンパイルされると、Expression<TDelegate>します。For these parameters, you can pass in a lambda expression and it will be compiled to an Expression<TDelegate>.

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>)メソッドを生成、MethodCallExpression呼び出しを表す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>)として構築されたジェネリック メソッド自体。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. これは、後、渡します、MethodCallExpressionCreateQuery<TElement>(Expression)のメソッド、IQueryProviderによって表される、Providerのプロパティ、outerパラメーター。It then passes the MethodCallExpression to the CreateQuery<TElement>(Expression) method of the IQueryProvider represented by the Provider property of the outer parameter.

呼び出し元を表す式ツリーを実行した結果として発生するクエリの動作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>)の型の実装によって異なります、outerパラメーター。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. 想定される動作は、outerKeySelectorinnerKeySelector関数を使用してからキーを抽出outerinner、それぞれします。The expected behavior is that the outerKeySelector and innerKeySelector functions are used to extract keys from outer and inner, respectively. これらのキーが等しいかどうかを使用して比較comparerします。These keys are compared for equality by using comparer. 内の各要素に一致するように、比較の結果を使用しています。outerから 0 個以上の要素を持つinnerします。The outcome of the comparisons is used to match each element in outer with zero or more elements from inner. 次に、resultSelector相関関係を持つ要素の各グループからの結果オブジェクトを射影する関数が呼び出されます。Then the resultSelector function is invoked to project a result object from each group of correlated elements.

適用対象