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联接方法 (LINQ to Entities)

  • 项目

LINQ to Entities 支持大多数 LINQ 联接方法，但不支持接受 IEqualityComparer 的联接方法，原因是比较器不能转换为数据源。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联接方法。

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

GroupJoin

支持

 
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

不支持

 
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

支持

 
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

不支持

 
 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
)

另请参见

概念

支持的和不支持的方法 (LINQ to Entities)