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支援與不支援的 LINQ 方法 (LINQ to Entities)

本節提供 LINQ to Entities 查詢中支援或不支援 Language-Integrated Query (LINQ) 標準查詢運算子的相關資訊。 許多 LINQ 標準查詢運算子都有一個可接受整數引數的多載版本。 此整數引數會對應至所操作序列中以零起始的索引 (IEqualityComparer<T>IComparer<T>)。 除非另外指定,否則不支援 LINQ 標準查詢運算子的這些多載版本,而且嘗試使用它們將會擲回例外狀況。

投影和限制方法

LINQ to Entities 查詢中支援大部分 LINQ 投影和限制方法,但接受位置引數者除外。 如需詳細資訊,請參閱 LINQ to Entities 查詢中的標準查詢運算子。 下表所列為支援及不支援的投影和限制方法。

方法 支援 Visual Basic 函式簽章 C# 方法簽章
Select 支援 Function Select(Of TSource, TResult) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, TResult)) _ ) As IQueryable(Of TResult) IQueryable<TResult> Select<TSource, TResult>( this IQueryable<TSource> source, Expression<Func<TSource, TResult>> selector )
Select 不支援 Function Select(Of TSource, TResult) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Integer, TResult)) _ ) As IQueryable(Of TResult) IQueryable<TResult> Select<TSource, TResult>( this IQueryable<TSource> source, Expression<Func<TSource, int, TResult>> selector )
SelectMany 支援 Function SelectMany(Of TSource, TResult) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, IEnumerable(Of TResult))) _ ) As IQueryable(Of TResult) IQueryable<TResult> SelectMany<TSource, TResult>( this IQueryable<TSource> source, Expression<Func<TSource, IEnumerable<TResult>>> selector )
SelectMany 不支援 Function SelectMany(Of TSource, TResult) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Integer, IEnumerable(Of TResult))) _ ) As IQueryable(Of TResult) IQueryable<TResult> SelectMany<TSource, TResult>( this IQueryable<TSource> source, Expression<Func<TSource, int, IEnumerable<TResult>>> selector )
SelectMany 支援 Function SelectMany(Of TSource, TCollection, TResult) ( _ source As IQueryable(Of TSource), _ collectionSelector As Expression(Of Func(Of TSource, IEnumerable(Of TCollection))), _ resultSelector As Expression(Of Func(Of TSource, TCollection, TResult)) _ ) As IQueryable(Of TResult) IQueryable<TResult> SelectMany\<TSource, TCollection, TResult>( this IQueryable<TSource> source, Expression<Func<TSource, IEnumerable<TCollection>>> collectionSelector, Expression<Func\<TSource, TCollection, TResult>> resultSelector )
SelectMany 不支援 Function SelectMany(Of TSource, TCollection, TResult) ( _ source As IQueryable(Of TSource), _ collectionSelector As Expression(Of Func(Of TSource, Integer, IEnumerable(Of TCollection))), _ resultSelector As Expression(Of Func(Of TSource, TCollection, TResult)) _ ) As IQueryable(Of TResult) IQueryable<TResult> SelectMany\<TSource, TCollection, TResult>( this IQueryable<TSource> source, Expression<Func<TSource, int, IEnumerable<TCollection>>> collectionSelector, Expression<Func\<TSource, TCollection, TResult>> resultSelector )
Where 支援 Function Where(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Boolean)) _ ) As IQueryable(Of TSource) IQueryable<TSource> Where<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, bool>> predicate )
Where 不支援 Function Where(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Integer, Boolean)) _ ) As IQueryable(Of TSource) IQueryable<TSource> Where<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, int, bool>> predicate )

聯結方法

LINQ to Entities 中支援大部分 LINQ 聯結方法,但接受 IEqualityComparer 者除外,因為比較子無法轉譯成資料來源。 如需詳細資訊,請參閱 LINQ to Entities 查詢中的標準查詢運算子。 下表所列為支援及不支援的聯結方法。

方法 支援 Visual Basic 函式簽章 C# 方法簽章
GroupJoin 支援 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) IQueryable<TResult> GroupJoin<TOuter, TInner, TKey, TResult>( this IQueryable<TOuter> outer, IEnumerable<TInner> inner, Expression<Func<TOuter, TKey>> outerKeySelector, Expression<Func<TInner, TKey>> innerKeySelector, Expression<Func<TOuter, IEnumerable<TInner>, TResult>> resultSelector )
GroupJoin 不支援 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) IQueryable<TResult> GroupJoin\<TOuter, TInner, TKey, TResult>( this IQueryable<TOuter> outer, IEnumerable<TInner> inner, Expression<Func\<TOuter, TKey>> outerKeySelector, Expression<Func\<TInner, TKey>> innerKeySelector, Expression<Func<TOuter, IEnumerable<TInner>, TResult>> resultSelector, IEqualityComparer<TKey> comparer )
Join 支援 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) IQueryable<TResult> Join<TOuter, TInner, TKey, TResult>( this IQueryable<TOuter> outer, IEnumerable<TInner> inner, Expression<Func<TOuter, TKey>> outerKeySelector, Expression<Func<TInner, TKey>> innerKeySelector, Expression<Func<TOuter, TInner, TResult>> resultSelector )
Join 不支援 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) IQueryable<TResult> Join\<TOuter, TInner, TKey, TResult>( this IQueryable<TOuter> outer, IEnumerable<TInner> inner, Expression<Func\<TOuter, TKey>> outerKeySelector, Expression<Func\<TInner, TKey>> innerKeySelector, Expression<Func\<TOuter, TInner, TResult>> resultSelector, IEqualityComparer<TKey> comparer )

設定方法

LINQ to Entities 查詢中支援大部分 LINQ 設定方法,但使用 EqualityComparer<T> 者除外。 如需詳細資訊,請參閱 LINQ to Entities 查詢中的標準查詢運算子。 下表所列為支援及不支援的設定方法。

方法 支援 Visual Basic 函式簽章 C# 方法簽章
All 支援 Function All(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Boolean)) _ ) As Boolean bool All<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, bool>> predicate )
Any 支援 Function Any(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As Boolean bool Any<TSource>( this IQueryable<TSource> source )
Any 支援 Function Any(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Boolean)) _ ) As Boolean bool Any<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, bool>> predicate )
Contains 已支援 Function Contains(Of TSource) ( _ source As IQueryable(Of TSource), _ item As TSource _ ) As Boolean bool Contains<TSource>( this IQueryable<TSource> source, TSource item )
Contains 不支援 Function Contains(Of TSource) ( _ source As IQueryable(Of TSource), _ item As TSource, _ comparer As IEqualityComparer(Of TSource) _ ) As Boolean bool Contains<TSource>( this IQueryable<TSource> source, TSource item, IEqualityComparer<TSource> comparer )
Concat 支援,但是不

保證會維持排序
Function Concat(Of TSource) ( _ source1 As IQueryable(Of TSource), _ source2 As IEnumerable(Of TSource) _ ) As IQueryable(Of TSource) IQueryable<TSource> Concat<TSource>( this IQueryable<TSource> source1, IEnumerable<TSource> source2 )
DefaultIfEmpty 支援 Function DefaultIfEmpty(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As IQueryable(Of TSource) IQueryable<TSource> DefaultIfEmpty<TSource>( this IQueryable<TSource> source )
DefaultIfEmpty 支援 Function DefaultIfEmpty(Of TSource) ( _ source As IQueryable(Of TSource), _ defaultValue As TSource _ ) As IQueryable(Of TSource) IQueryable<TSource> DefaultIfEmpty<TSource>( this IQueryable<TSource> source, TSource defaultValue )
Distinct 已支援 Function Distinct(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As IQueryable(Of TSource) IQueryable<TSource> Distinct<TSource>( this IQueryable<TSource> source )
Distinct 不支援 Function Distinct(Of TSource) ( _ source As IQueryable(Of TSource), _ comparer As IEqualityComparer(Of TSource) _ ) As IQueryable(Of TSource) IQueryable<TSource> Distinct<TSource>( this IQueryable<TSource> source, IEqualityComparer<TSource> comparer )
Except 支援 Function Except(Of TSource) ( _ source1 As IQueryable(Of TSource), _ source2 As IEnumerable(Of TSource) _ ) As IQueryable(Of TSource) IQueryable<TSource> Except<TSource>( this IQueryable<TSource> source1, IEnumerable<TSource> source2 )
Except 不支援 Function Except(Of TSource) ( _ source1 As IQueryable(Of TSource), _ source2 As IEnumerable(Of TSource), _ comparer As IEqualityComparer(Of TSource) _ ) As IQueryable(Of TSource) IQueryable<TSource> Except<TSource>( this IQueryable<TSource> source1, IEnumerable<TSource> source2, IEqualityComparer<TSource> comparer )
Intersect 支援 Function Intersect(Of TSource) ( _ source1 As IQueryable(Of TSource), _ source2 As IEnumerable(Of TSource) _ ) As IQueryable(Of TSource) IQueryable<TSource> Intersect<TSource>( this IQueryable<TSource> source1, IEnumerable<TSource> source2 )
Intersect 不支援 Function Intersect(Of TSource) ( _ source1 As IQueryable(Of TSource), _ source2 As IEnumerable(Of TSource), _ comparer As IEqualityComparer(Of TSource) _ ) As IQueryable(Of TSource) IQueryable<TSource> Intersect<TSource>( this IQueryable<TSource> source1, IEnumerable<TSource> source2, IEqualityComparer<TSource> comparer )
Union 支援 Function Union(Of TSource) ( _ source1 As IQueryable(Of TSource), _ source2 As IEnumerable(Of TSource) _ ) As IQueryable(Of TSource) IQueryable<TSource> Union<TSource>( this IQueryable<TSource> source1, IEnumerable<TSource> source2 )
Union 不支援 Function Union(Of TSource) ( _ source1 As IQueryable(Of TSource), _ source2 As IEnumerable(Of TSource), _ comparer As IEqualityComparer(Of TSource) _ ) As IQueryable(Of TSource) IQueryable<TSource> Union<TSource>( this IQueryable<TSource> source1, IEnumerable<TSource> source2, IEqualityComparer<TSource> comparer )

排序方法

LINQ to Entities 中支援大部分 LINQ 排序方法,但接受 IComparer<T> 者除外,因為比較子無法轉譯成資料來源。 如需詳細資訊,請參閱 LINQ to Entities 查詢中的標準查詢運算子。 下表所列為支援及不支援的排序方法。

方法 支援 Visual Basic 函式簽章 C# 方法簽章
OrderBy 支援 Function OrderBy(Of TSource, TKey) ( _ source As IQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)) _ ) As IOrderedQueryable(Of TSource) IOrderedQueryable<TSource> OrderBy<TSource, TKey>( this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector )
OrderBy 不支援 Function OrderBy(Of TSource, TKey) ( _ source As IQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)), _ comparer As IComparer(Of TKey) _ ) As IOrderedQueryable(Of TSource) IOrderedQueryable<TSource> OrderBy\<TSource, TKey>( this IQueryable<TSource> source, Expression<Func\<TSource, TKey>> keySelector, IComparer<TKey> comparer )
OrderByDescending 支援 Function OrderByDescending(Of TSource, TKey) ( _ source As IQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)) _ ) As IOrderedQueryable(Of TSource) IOrderedQueryable<TSource> OrderByDescending<TSource, TKey>( this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector )
OrderByDescending 不支援 Function OrderByDescending(Of TSource, TKey) ( _ source As IQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)), _ comparer As IComparer(Of TKey) _ ) As IOrderedQueryable(Of TSource) IOrderedQueryable<TSource> OrderByDescending\<TSource, TKey>( this IQueryable<TSource> source, Expression<Func\<TSource, TKey>> keySelector, IComparer<TKey> comparer )
ThenBy 支援 Function ThenBy(Of TSource, TKey) ( _ source As IOrderedQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)) _ ) As IOrderedQueryable(Of TSource) IOrderedQueryable<TSource> ThenBy<TSource, TKey>( this IOrderedQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector )
ThenBy 不支援 Function ThenBy(Of TSource, TKey) ( _ source As IOrderedQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)), _ comparer As IComparer(Of TKey) _ ) As IOrderedQueryable(Of TSource) IOrderedQueryable<TSource> ThenBy\<TSource, TKey>( this IOrderedQueryable<TSource> source, Expression<Func\<TSource, TKey>> keySelector, IComparer<TKey> comparer )
ThenByDescending 支援 Function ThenByDescending(Of TSource, TKey) ( _ source As IOrderedQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)) _ ) As IOrderedQueryable(Of TSource) IOrderedQueryable<TSource> ThenByDescending<TSource, TKey>( this IOrderedQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector )
ThenByDescending 不支援 Function ThenByDescending(Of TSource, TKey) ( _ source As IOrderedQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)), _ comparer As IComparer(Of TKey) _ ) As IOrderedQueryable(Of TSource) IOrderedQueryable<TSource> ThenByDescending\<TSource, TKey>( this IOrderedQueryable<TSource> source, Expression<Func\<TSource, TKey>> keySelector, IComparer<TKey> comparer )
Reverse 不支援 Function Reverse(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As IQueryable(Of TSource) IQueryable<TSource> Reverse<TSource>( this IQueryable<TSource> source )

群組方法

LINQ to Entities 中支援大部分 LINQ 群組方法,但接受 IEqualityComparer<T> 者除外,因為比較子無法轉譯成資料來源。 如需詳細資訊,請參閱 LINQ to Entities 查詢中的標準查詢運算子。 下表所列為支援及不支援的群組方法。

方法 支援 Visual Basic 函式簽章 C# 方法簽章
GroupBy 支援 Function GroupBy(Of TSource, TKey) ( _ source As IQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)) _ ) As IQueryable(Of IGrouping(Of TKey, TSource)) IQueryable<IGrouping<TKey, TSource>> GroupBy<TSource, TKey>( this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector )
GroupBy 不支援 Function GroupBy(Of TSource, TKey) ( _ source As IQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)), _ comparer As IEqualityComparer(Of TKey) _ ) As IQueryable(Of IGrouping(Of TKey, TSource)) IQueryable<IGrouping\<TKey, TSource>> GroupBy\<TSource, TKey>( this IQueryable<TSource> source, Expression<Func\<TSource, TKey>> keySelector, IEqualityComparer<TKey> comparer )
GroupBy 支援 Function GroupBy(Of TSource, TKey, TElement) ( _ source As IQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)), _ elementSelector As Expression(Of Func(Of TSource, TElement)) _ ) As IQueryable(Of IGrouping(Of TKey, TElement)) IQueryable<IGrouping<TKey, TElement>> GroupBy<TSource, TKey, TElement>( this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, Expression<Func<TSource, TElement>> elementSelector )
GroupBy 已支援 Function GroupBy(Of TSource, TKey, TResult) ( _ source As IQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)), _ resultSelector As Expression(Of Func(Of TKey, IEnumerable(Of TSource), TResult)) _ ) As IQueryable(Of TResult) IQueryable<TResult> GroupBy\<TSource, TKey, TResult>( this IQueryable<TSource> source, Expression<Func\<TSource, TKey>> keySelector, Expression<Func<TKey, IEnumerable<TSource>, TResult>> resultSelector )
GroupBy 不支援 Function GroupBy(Of TSource, TKey, TElement) ( _ source As IQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)), _ elementSelector As Expression(Of Func(Of TSource, TElement)), _ comparer As IEqualityComparer(Of TKey) _ ) As IQueryable(Of IGrouping(Of TKey, TElement)) IQueryable<IGrouping\<TKey, TElement>> GroupBy\<TSource, TKey, TElement>( this IQueryable<TSource> source, Expression<Func\<TSource, TKey>> keySelector, Expression<Func\<TSource, TElement>> elementSelector, IEqualityComparer<TKey> comparer
GroupBy 支援 Function GroupBy(Of TSource, TKey, TElement, TResult) ( _ source As IQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)), _ elementSelector As Expression(Of Func(Of TSource, TElement)), _ resultSelector As Expression(Of Func(Of TKey, IEnumerable(Of TElement), TResult)) _ ) As IQueryable(Of TResult) IQueryable<TResult> GroupBy<TSource, TKey, TElement, TResult>( this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, Expression<Func<TSource, TElement>> elementSelector, Expression<Func<TKey, IEnumerable<TElement>, TResult>> resultSelector )
GroupBy 不支援 Function GroupBy(Of TSource, TKey, TResult) ( _ source As IQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)), _ resultSelector As Expression(Of Func(Of TKey, IEnumerable(Of TSource), TResult)), _ comparer As IEqualityComparer(Of TKey) _ ) As IQueryable(Of TResult) IQueryable<TResult> GroupBy\<TSource, TKey, TResult>( this IQueryable<TSource> source, Expression<Func\<TSource, TKey>> keySelector, Expression<Func<TKey, IEnumerable<TSource>, TResult>> resultSelector, IEqualityComparer<TKey> comparer )
GroupBy 不支援 Function GroupBy(Of TSource, TKey, TElement, TResult) ( _ source As IQueryable(Of TSource), _ keySelector As Expression(Of Func(Of TSource, TKey)), _ elementSelector As Expression(Of Func(Of TSource, TElement)), _ resultSelector As Expression(Of Func(Of TKey, IEnumerable(Of TElement), TResult)), _ comparer As IEqualityComparer(Of TKey) _ ) As IQueryable(Of TResult) IQueryable<TResult> GroupBy<TSource, TKey, TElement, TResult>( this IQueryable<TSource> source, Expression<Func<TSource, TKey>> keySelector, Expression<Func<TSource, TElement>> elementSelector, Expression<Func<TKey, IEnumerable<TElement>, TResult>> resultSelector, IEqualityComparer<TKey> comparer )

彙總方法

LINQ to Entities 中支援大部分接受基本資料類型的彙總方法。 如需詳細資訊,請參閱 LINQ to Entities 查詢中的標準查詢運算子。 下表所列為支援及不支援的彙總方法。

方法 支援 Visual Basic 函式簽章 C# 方法簽章
Aggregate 不支援 Function Aggregate(Of TSource) ( _ source As IQueryable(Of TSource), _ func As Expression(Of Func(Of TSource, TSource, TSource)) _ ) As TSource TSource Aggregate<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, TSource, TSource>> func )
Aggregate 不支援 Function Aggregate(Of TSource, TAccumulate) ( _ source As IQueryable(Of TSource), _ seed As TAccumulate, _ func As Expression(Of Func(Of TAccumulate, TSource, TAccumulate)) _ ) As TAccumulate TAccumulate Aggregate<TSource, TAccumulate>( this IQueryable<TSource> source, TAccumulate seed, Expression<Func<TAccumulate, TSource, TAccumulate>> func )
Aggregate 不支援 Function Aggregate(Of TSource, TAccumulate, TResult) ( _ source As IQueryable(Of TSource), _ seed As TAccumulate, _ func As Expression(Of Func(Of TAccumulate, TSource, TAccumulate)), _ selector As Expression(Of Func(Of TAccumulate, TResult)) _ ) As TResult TResult Aggregate<TSource, TAccumulate, TResult>( this IQueryable<TSource> source, TAccumulate seed, Expression<Func<TAccumulate, TSource, TAccumulate>> func, Expression<Func<TAccumulate, TResult>> selector )
Average 支援 Function Average ( _ source As IQueryable(Of Decimal) _ ) As Decimal decimal Average( this IQueryable<decimal> source )
Average 支援 Function Average ( _ source As IQueryable(Of Double) _ ) As Double double Average( this IQueryable<double> source )
Average 支援 Function Average ( _ source As IQueryable(Of Integer) _ ) As Double double Average( this IQueryable<int> source )
Average 支援 Function Average ( _ source As IQueryable(Of Long) _ ) As Double double Average( this IQueryable<long> source )
Average 支援 Function Average ( _ source As IQueryable(Of Nullable(Of Decimal)) _ ) As Nullable(Of Decimal) Nullable<decimal> Average( this IQueryable<Nullable<decimal>> source )
Average 支援 Function Average ( _ source As IQueryable(Of Nullable(Of Double)) _ ) As Nullable(Of Double) Nullable<double> Average( this IQueryable<Nullable<double>> source )
Average 支援 Function Average ( _ source As IQueryable(Of Nullable(Of Integer)) _ ) As Nullable(Of Double) Nullable<double> Average( this IQueryable<Nullable<int>> source )
Average 支援 Function Average ( _ source As IQueryable(Of Nullable(Of Long)) _ ) As Nullable(Of Double) Nullable<double> Average( this IQueryable<Nullable<long>> source )
Average 支援 Function Average ( _ source As IQueryable(Of Nullable(Of Single)) _ ) As Nullable(Of Single) Nullable<float> Average( this IQueryable<Nullable<float>> source )
Average 已支援 Function Average ( _ source As IQueryable(Of Single) _ ) As Single float Average( this IQueryable<float> source )
Average 不支援 Function Average(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Integer)) _ ) As Double double Average<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, int>> selector )
Average 不支援 Function Average(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Nullable(Of Integer))) _ ) As Nullable(Of Double) Nullable<double> Average<TSource>( this IQueryable<TSource> source, Expression<Func<TSource, Nullable<int>>> selector )
Average 不支援 Function Average(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Long)) _ ) As Double double Average<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, long>> selector )
Average 不支援 Function Average(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Nullable(Of Long))) _ ) As Nullable(Of Double) Nullable<double> Average<TSource>( this IQueryable<TSource> source, Expression<Func<TSource, Nullable<long>>> selector )
Average 不支援 Function Average(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Single)) _ ) As Single float Average<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, float>> selector )
Average 不支援 Function Average(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Nullable(Of Single))) _ ) As Nullable(Of Single) Nullable<float> Average<TSource>( this IQueryable<TSource> source, Expression<Func<TSource, Nullable<float>>> selector )
Average 不支援 Function Average(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Double)) _ ) As Double double Average<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, double>> selector )
Average 不支援 Function Average(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Nullable(Of Double))) _ ) As Nullable(Of Double) Nullable<double> Average<TSource>( this IQueryable<TSource> source, Expression<Func<TSource, Nullable<double>>> selector )
Average 不支援 Function Average(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Decimal)) _ ) As Decimal decimal Average<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, decimal>> selector )
Average 不支援 Function Average(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Nullable(Of Decimal))) _ ) As Nullable(Of Decimal) Nullable<decimal> Average<TSource>( this IQueryable<TSource> source, Expression<Func<TSource, Nullable<decimal>>> selector )
Count 支援 Function Count(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As Integer int Count<TSource>( this IQueryable<TSource> source )
Count 不支援 Function Count(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Boolean)) _ ) As Integer int Count<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, bool>> predicate )
LongCount 支援 Function LongCount(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As Long long LongCount<TSource>( this IQueryable<TSource> source )
LongCount 不支援 Function LongCount(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Boolean)) _ ) As Long long LongCount<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, bool>> predicate )
Max 支援 Function Max(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As TSource TSource Max<TSource>( this IQueryable<TSource> source )
Max 不支援 Function Max(Of TSource, TResult) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, TResult)) _ ) As TResult TResult Max<TSource, TResult>( this IQueryable<TSource> source, Expression<Func<TSource, TResult>> selector )
Min 支援 Function Min(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As TSource TSource Min<TSource>( this IQueryable<TSource> source )
Min 不支援 Function Min(Of TSource, TResult) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, TResult)) _ ) As TResult TResult Min<TSource, TResult>( this IQueryable<TSource> source, Expression<Func<TSource, TResult>> selector )
Sum 支援 Function Sum ( _ source As IQueryable(Of Decimal) _ ) As Decimal decimal Sum( this IQueryable<decimal> source )
Sum 支援 Function Sum ( _ source As IQueryable(Of Double) _ ) As Double double Sum( this IQueryable<double> source
Sum 支援 Function Sum ( _ source As IQueryable(Of Integer) _ ) As Integer int Sum( this IQueryable<int> source )
Sum 支援 Function Sum ( _ source As IQueryable(Of Long) _ ) As Long long Sum( this IQueryable<long> source )
Sum 支援 Function Sum ( _ source As IQueryable(Of Nullable(Of Decimal)) _ ) As Nullable(Of Decimal) Nullable<decimal> Sum( this IQueryable<Nullable<decimal>> source )
Sum 支援 Function Sum ( _ source As IQueryable(Of Nullable(Of Double)) _ ) As Nullable(Of Double) Function Sum ( _ source As IQueryable(Of Nullable(Of Double)) _ ) As Nullable(Of Double)Nullable<double> Sum( this IQueryable<Nullable<double>> source )
Sum 支援 Function Sum ( _ source As IQueryable(Of Nullable(Of Integer)) _ ) As Nullable(Of Integer) Nullable<int> Sum( this IQueryable<Nullable<int>> source )
Sum 支援 Function Sum ( _ source As IQueryable(Of Nullable(Of Long)) _ ) As Nullable(Of Long) Nullable<long> Sum( this IQueryable<Nullable<long>> source )
Sum 支援 Function Sum ( _ source As IQueryable(Of Nullable(Of Single)) _ ) As Nullable(Of Single) Nullable<float> Sum( this IQueryable<Nullable<float>> source )
Sum 已支援 Function Sum ( _ source As IQueryable(Of Single) _ ) As Single float Sum( this IQueryable<float> source )
Sum 不支援 Function Sum(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Integer)) _ ) As Integer int Sum<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, int>> selector )
Sum 不支援 Function Sum(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Nullable(Of Integer))) _ ) As Nullable(Of Integer) Nullable<int> Sum<TSource>( this IQueryable<TSource> source, Expression<Func<TSource, Nullable<int>>> selector )
Sum 不支援 Function Sum(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Long)) _ ) As Long long Sum<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, long>> selector )
Sum 不支援 Function Sum(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Nullable(Of Long))) _ ) As Nullable(Of Long) Nullable<long> Sum<TSource>( this IQueryable<TSource> source, Expression<Func<TSource, Nullable<long>>> selector )
Sum 不支援 Function Sum(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Nullable(Of Single))) _ ) As Nullable(Of Single) Nullable<float> Sum<TSource>( this IQueryable<TSource> source, Expression<Func<TSource, Nullable<float>>> selector )
Sum 不支援 Function Sum(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Single)) _ ) As Single float Sum<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, float>> selector )
Sum 不支援 Function Sum(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Double)) _ ) As Double double Sum<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, double>> selector )
Sum 不支援 Function Sum(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Nullable(Of Double))) _ ) As Nullable(Of Double) Nullable<double> Sum<TSource>( this IQueryable<TSource> source, Expression<Func<TSource, Nullable<double>>> selector )
Sum 不支援 Function Sum(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Decimal)) _ ) As Decimal decimal Sum<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, decimal>> selector )
Sum 不支援 Function Sum(Of TSource) ( _ source As IQueryable(Of TSource), _ selector As Expression(Of Func(Of TSource, Nullable(Of Decimal))) _ ) As Nullable(Of Decimal) Nullable<decimal> Sum<TSource>( this IQueryable<TSource> source, Expression<Func<TSource, Nullable<decimal>>> selector )

型別方法

Entity Framework 中支援處理 CLR 類型轉換和測試的 LINQ 標準查詢運算子。 LINQ to Entities 中僅支援對應到概念模型型別的 CLR 型別。 如需概念模型類型清單,請參閱概念模型類型 (CSDL)。 下表所列為支援及不支援的型別方法。

方法 支援 Visual Basic 函式簽章 C# 方法簽章
Cast 支援 EDM 基本型別 Function Cast(Of TResult) ( _ source As IQueryable _ ) As IQueryable(Of TResult) IQueryable<TResult> Cast<TResult>( this IQueryable source )
OfType 支援 EntityType Function OfType(Of TResult) ( _ source As IQueryable _ ) As IQueryable(Of TResult) IQueryable<TResult> OfType<TResult>( this IQueryable source )

分頁方法

LINQ to Entities 查詢中不支援一些 LINQ 分頁方法。 如需詳細資訊,請參閱 LINQ to Entities 查詢中的標準查詢運算子。 下表所列為支援和不支援的分頁方法。

方法 支援 Visual Basic 函式簽章 C# 方法簽章
ElementAt 不支援 Function ElementAt(Of TSource) ( _ source As IQueryable(Of TSource), _ index As Integer _ ) As TSource TSource ElementAt<TSource>( this IQueryable<TSource> source, int index )
ElementAtOrDefault 不支援 Function ElementAtOrDefault(Of TSource) ( _ source As IQueryable(Of TSource), _ index As Integer _ ) As TSource TSource ElementAtOrDefault<TSource>( this IQueryable<TSource> source, int index )
First 支援 Function First(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As TSource TSource First<TSource>( this IQueryable<TSource> source )
First 支援 Function First(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Boolean)) _ ) As TSource TSource First<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, bool>> predicate )
FirstOrDefault 支援 Function FirstOrDefault(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As TSource TSource FirstOrDefault<TSource>( this IQueryable<TSource> source )
FirstOrDefault 已支援 Function FirstOrDefault(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Boolean)) _ ) As TSource TSource FirstOrDefault<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, bool>> predicate )
Last 不支援 Function Last(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As TSource TSource Last<TSource>( this IQueryable<TSource> source )
Last 不支援 Function Last(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Boolean)) _ ) As TSource TSource Last<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, bool>> predicate )
LastOrDefault 不支援 Function LastOrDefault(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As TSource TSource LastOrDefault<TSource>( this IQueryable<TSource> source )
LastOrDefault 不支援 Function LastOrDefault(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Boolean)) _ ) As TSource TSource LastOrDefault<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, bool>> predicate )
Single 支援 Function Single(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As TSource TSource Single<TSource>( this IQueryable<TSource> source )
Single 支援 Function Single(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Boolean)) _ ) As TSource TSource Single<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, bool>> predicate )
SingleOrDefault 支援 Function SingleOrDefault(Of TSource) ( _ source As IQueryable(Of TSource) _ ) As TSource TSource SingleOrDefault<TSource>( this IQueryable<TSource> source )
SingleOrDefault 支援 Function SingleOrDefault(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Boolean)) _ ) As TSource TSource SingleOrDefault<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, bool>> predicate )
Skip 已支援 Function Skip(Of TSource) ( _ source As IQueryable(Of TSource), _ count As Integer _ ) As IQueryable(Of TSource) IQueryable<TSource> Skip<TSource>( this IQueryable<TSource> source, int count )
SkipWhile 不支援 Function SkipWhile(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Boolean)) _ ) As IQueryable(Of TSource) IQueryable<TSource> SkipWhile<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, bool>> predicate )
SkipWhile 不支援 Function SkipWhile(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Integer, Boolean)) _ ) As IQueryable(Of TSource) IQueryable<TSource> SkipWhile<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, int, bool>> predicate )
Take 支援 Function Take(Of TSource) ( _ source As IQueryable(Of TSource), _ count As Integer _ ) As IQueryable(Of TSource) IQueryable<TSource> Take<TSource>( this IQueryable<TSource> source, int count )
TakeWhile 不支援 Function TakeWhile(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Boolean)) _ ) As IQueryable(Of TSource) IQueryable<TSource> TakeWhile<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, bool>> predicate )
TakeWhile 不支援 Function TakeWhile(Of TSource) ( _ source As IQueryable(Of TSource), _ predicate As Expression(Of Func(Of TSource, Integer, Boolean)) _ ) As IQueryable(Of TSource) IQueryable<TSource> TakeWhile<TSource>( this IQueryable<TSource> source, Expression<Func\<TSource, int, bool>> predicate )

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