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投影和限制方法 (LINQ to Entities)

  • 项目

LINQ to Entities 查询中支持大多数 LINQ 投影和限制方法，除了那些接受位置参数的方法。有关更多信息，请参见 LINQ to Entities 查询中的标准查询运算符。下表列出了支持的和不支持的投影和限制方法。

支持的和不支持的方法

方法 支持 Visual Basic 函数签名 C# 方法签名

Select

支持

 
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

不支持

 
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

支持

 
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

不支持

 
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

支持

 
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

不支持

 
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

支持

 
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

不支持

 
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
)

另请参见

概念

支持的和不支持的方法 (LINQ to Entities)