Queryable.Except Method
Definition
Important
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Produces the set difference of two sequences.
Overloads
Except<TSource>(IQueryable<TSource>, IEnumerable<TSource>) |
Produces the set difference of two sequences by using the default equality comparer to compare values. |
Except<TSource>(IQueryable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) |
Produces the set difference of two sequences by using the specified IEqualityComparer<T> to compare values. |
Except<TSource>(IQueryable<TSource>, IEnumerable<TSource>)
- Source:
- Queryable.cs
- Source:
- Queryable.cs
- Source:
- Queryable.cs
Produces the set difference of two sequences by using the default equality comparer to compare values.
public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static System::Linq::IQueryable<TSource> ^ Except(System::Linq::IQueryable<TSource> ^ source1, System::Collections::Generic::IEnumerable<TSource> ^ source2);
public static System.Linq.IQueryable<TSource> Except<TSource> (this System.Linq.IQueryable<TSource> source1, System.Collections.Generic.IEnumerable<TSource> source2);
static member Except : System.Linq.IQueryable<'Source> * seq<'Source> -> System.Linq.IQueryable<'Source>
<Extension()>
Public Function Except(Of TSource) (source1 As IQueryable(Of TSource), source2 As IEnumerable(Of TSource)) As IQueryable(Of TSource)
Type Parameters
- TSource
The type of the elements of the input sequences.
Parameters
- source1
- IQueryable<TSource>
An IQueryable<T> whose elements that are not also in source2
will be returned.
- source2
- IEnumerable<TSource>
An IEnumerable<T> whose elements that also occur in the first sequence will not appear in the returned sequence.
Returns
An IQueryable<T> that contains the set difference of the two sequences.
Exceptions
source1
or source2
is null
.
Examples
The following code example demonstrates how to use Except<TSource>(IQueryable<TSource>, IEnumerable<TSource>) to return those elements that only appear in the first source sequence.
double[] numbers1 = { 2.0, 2.1, 2.2, 2.3, 2.4, 2.5 };
double[] numbers2 = { 2.2 };
// Get the numbers from the first array that
// are NOT in the second array.
IEnumerable<double> onlyInFirstSet =
numbers1.AsQueryable().Except(numbers2);
foreach (double number in onlyInFirstSet)
Console.WriteLine(number);
/*
This code produces the following output:
2
2.1
2.3
2.4
2.5
*/
Dim numbers1() As Double = {2.0, 2.1, 2.2, 2.3, 2.4, 2.5}
Dim numbers2() As Double = {2.2}
' Get the numbers from the first array that
' are NOT in the second array.
Dim onlyInFirstSet As IEnumerable(Of Double) = _
numbers1.AsQueryable().Except(numbers2)
Dim output As New System.Text.StringBuilder
For Each number As Double In onlyInFirstSet
output.AppendLine(number)
Next
' Display the output.
MsgBox(output.ToString())
' This code produces the following output:
'
' 2
' 2.1
' 2.3
' 2.4
' 2.5
Remarks
The Except<TSource>(IQueryable<TSource>, IEnumerable<TSource>) method generates a MethodCallExpression that represents calling Except<TSource>(IQueryable<TSource>, IEnumerable<TSource>) itself as a constructed generic method. It then passes the MethodCallExpression to the CreateQuery<TElement>(Expression) method of the IQueryProvider represented by the Provider property of thesource1
parameter.
The query behavior that occurs as a result of executing an expression tree that represents calling Except<TSource>(IQueryable<TSource>, IEnumerable<TSource>) depends on the implementation of the type of the source1
parameter. The expected behavior is that all the elements in source1
are returned except for those that are also in source2
.
Applies to
Except<TSource>(IQueryable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)
- Source:
- Queryable.cs
- Source:
- Queryable.cs
- Source:
- Queryable.cs
Produces the set difference of two sequences by using the specified IEqualityComparer<T> to compare values.
public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static System::Linq::IQueryable<TSource> ^ Except(System::Linq::IQueryable<TSource> ^ source1, System::Collections::Generic::IEnumerable<TSource> ^ source2, System::Collections::Generic::IEqualityComparer<TSource> ^ comparer);
public static System.Linq.IQueryable<TSource> Except<TSource> (this System.Linq.IQueryable<TSource> source1, System.Collections.Generic.IEnumerable<TSource> source2, System.Collections.Generic.IEqualityComparer<TSource> comparer);
public static System.Linq.IQueryable<TSource> Except<TSource> (this System.Linq.IQueryable<TSource> source1, System.Collections.Generic.IEnumerable<TSource> source2, System.Collections.Generic.IEqualityComparer<TSource>? comparer);
static member Except : System.Linq.IQueryable<'Source> * seq<'Source> * System.Collections.Generic.IEqualityComparer<'Source> -> System.Linq.IQueryable<'Source>
<Extension()>
Public Function Except(Of TSource) (source1 As IQueryable(Of TSource), source2 As IEnumerable(Of TSource), comparer As IEqualityComparer(Of TSource)) As IQueryable(Of TSource)
Type Parameters
- TSource
The type of the elements of the input sequences.
Parameters
- source1
- IQueryable<TSource>
An IQueryable<T> whose elements that are not also in source2
will be returned.
- source2
- IEnumerable<TSource>
An IEnumerable<T> whose elements that also occur in the first sequence will not appear in the returned sequence.
- comparer
- IEqualityComparer<TSource>
An IEqualityComparer<T> to compare values.
Returns
An IQueryable<T> that contains the set difference of the two sequences.
Exceptions
source1
or source2
is null
.
Remarks
The Except<TSource>(IQueryable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) method generates a MethodCallExpression that represents calling Except<TSource>(IQueryable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) itself as a constructed generic method. It then passes the MethodCallExpression to the CreateQuery<TElement>(Expression) method of the IQueryProvider represented by the Provider property of thesource1
parameter.
The query behavior that occurs as a result of executing an expression tree that represents calling Except<TSource>(IQueryable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) depends on the implementation of the type of the source1
parameter. The expected behavior is that all the elements in source1
are returned except for those that are also in source2
, and comparer
is used to compare values.