Class QueryableExtensions
Holds extension methods for System.Linq.IQueryable.
Inheritance
Inherited Members
Namespace: Telerik.Windows.Data
Assembly: Telerik.Windows.Data.dll
Syntax
public static class QueryableExtensions
Methods
Aggregate(IQueryable, IEnumerable<AggregateFunction>)
Calculates the results of given aggregates functions on a sequence of elements.
Declaration
public static AggregateResultCollection Aggregate(this IQueryable source, IEnumerable<AggregateFunction> aggregateFunctions)
Parameters
System.Linq.IQueryable
source
An System.Linq.IQueryable whose elements will be used for aggregate calculation. |
System.Collections.Generic.IEnumerable<AggregateFunction>
aggregateFunctions
The aggregate functions. |
Returns
AggregateResultCollection
Collection of AggregateResults calculated for each function. |
Aggregate(IQueryable, AggregateFunction)
Calculates the results of a given aggregate function on a sequence of elements.
Declaration
public static AggregateResultCollection Aggregate(this IQueryable source, AggregateFunction aggregateFunction)
Parameters
System.Linq.IQueryable
source
An System.Linq.IQueryable whose elements will be used for aggregate calculation. |
AggregateFunction
aggregateFunction
The aggregate function. |
Returns
AggregateResultCollection
Collection of AggregateResults calculated for the function. |
Count(IQueryable)
Returns the number of elements in a sequence.
Declaration
public static int Count(this IQueryable source)
Parameters
System.Linq.IQueryable
source
The System.Linq.IQueryable that contains the elements to be counted. |
Returns
System.Int32
The number of elements in the input sequence. |
Exceptions
System.ArgumentNullException
|
ElementAt(IQueryable, Int32)
Returns the element at a specified index in a sequence.
Declaration
public static object ElementAt(this IQueryable source, int index)
Parameters
System.Linq.IQueryable
source
An System.Linq.IQueryable to return an element from. |
System.Int32
index
The zero-based index of the element to retrieve. |
Returns
System.Object
The element at the specified position in |
Exceptions
System.ArgumentNullException
|
System.ArgumentOutOfRangeException
|
Except(IQueryable, IQueryable)
Produces the set difference of two sequences by using the default equality comparer to compare values.
Declaration
public static IQueryable Except(this IQueryable source1, IQueryable source2)
Parameters
System.Linq.IQueryable
source1
|
System.Linq.IQueryable
source2
|
Returns
System.Linq.IQueryable
|
First(IQueryable)
Returns the firsts item in a sequence.
Declaration
public static object First(this IQueryable source)
Parameters
System.Linq.IQueryable
source
The System.Linq.IQueryable that contains the elements to be counted. |
Returns
System.Object
First element. |
GroupBy(IQueryable, IEnumerable<IGroupDescriptor>)
Groups the elements of a sequence according to a specified groupDescriptors
.
Declaration
public static IQueryable GroupBy(this IQueryable source, IEnumerable<IGroupDescriptor> groupDescriptors)
Parameters
System.Linq.IQueryable
source
An System.Linq.IQueryable whose elements to group. |
System.Collections.Generic.IEnumerable<IGroupDescriptor>
groupDescriptors
The group descriptors used for grouping. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable with IGroup items, whose elements contains a sequence of objects and a key. |
GroupBy(IQueryable, LambdaExpression)
Groups the elements of a sequence according to a specified key selector function.
Declaration
public static IQueryable GroupBy(this IQueryable source, LambdaExpression keySelector)
Parameters
System.Linq.IQueryable
source
An System.Linq.IQueryable whose elements to group. |
System.Linq.Expressions.LambdaExpression
keySelector
A function to extract the key for each element. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable with System.Linq.IGrouping<, > items, whose elements contains a sequence of objects and a key. |
OrderBy(IQueryable, LambdaExpression)
Sorts the elements of a sequence in ascending order according to a key.
Declaration
public static IQueryable OrderBy(this IQueryable source, LambdaExpression keySelector)
Parameters
System.Linq.IQueryable
source
A sequence of values to order. |
System.Linq.Expressions.LambdaExpression
keySelector
A function to extract a key from an element. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable whose elements are sorted according to a key. |
OrderBy(IQueryable, LambdaExpression, Nullable<ListSortDirection>)
Calls OrderBy(IQueryable, LambdaExpression)
or OrderByDescending(IQueryable, LambdaExpression) depending on the sortDirection
.
Declaration
public static IQueryable OrderBy(this IQueryable source, LambdaExpression keySelector, ListSortDirection? sortDirection)
Parameters
System.Linq.IQueryable
source
The source. |
System.Linq.Expressions.LambdaExpression
keySelector
The key selector. |
System.Nullable<System.ComponentModel.ListSortDirection>
sortDirection
The sort direction. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable whose elements are sorted according to a key. |
OrderByDescending(IQueryable, LambdaExpression)
Sorts the elements of a sequence in descending order according to a key.
Declaration
public static IQueryable OrderByDescending(this IQueryable source, LambdaExpression keySelector)
Parameters
System.Linq.IQueryable
source
A sequence of values to order. |
System.Linq.Expressions.LambdaExpression
keySelector
A function to extract a key from an element. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable whose elements are sorted in descending order according to a key. |
Page(IQueryable, Int32, Int32)
Pages through the elements of a sequence until the specified
pageIndex
using pageSize
.
Declaration
public static IQueryable Page(this IQueryable source, int pageIndex, int pageSize)
Parameters
System.Linq.IQueryable
source
A sequence of values to page. |
System.Int32
pageIndex
Index of the page. |
System.Int32
pageSize
Size of the page. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable whose elements are at the specified |
Select(IQueryable, IEnumerable<ISelectDescriptor>)
Selects a sequence of objects based on a IEnumerable of SelectDescriptor.
Declaration
public static IQueryable Select(this IQueryable source, IEnumerable<ISelectDescriptor> selectDescriptors)
Parameters
System.Linq.IQueryable
source
The source. |
System.Collections.Generic.IEnumerable<ISelectDescriptor>
selectDescriptors
The select descriptor enumerable. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable that contains elements from the input sequence
that will be projected according to the specified |
Select(IQueryable, LambdaExpression)
Projects each element of a sequence into a new form.
Declaration
public static IQueryable Select(this IQueryable source, LambdaExpression selector)
Parameters
System.Linq.IQueryable
source
A sequence of values to project. |
System.Linq.Expressions.LambdaExpression
selector
A projection function to apply to each element. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable whose elements are the result of invoking a
projection selector on each element of |
Select(IQueryable, SelectDescriptorCollection)
Selects a sequence of objects based on a SelectDescriptorCollection.
Declaration
public static IQueryable Select(this IQueryable source, SelectDescriptorCollection selectDescriptors)
Parameters
System.Linq.IQueryable
source
The source. |
SelectDescriptorCollection
selectDescriptors
The select descriptor collection. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable that contains elements from the input sequence
that will be projected according to the specified |
Skip(IQueryable, Int32)
Bypasses a specified number of elements in a sequence and then returns the remaining elements.
Declaration
public static IQueryable Skip(this IQueryable source, int count)
Parameters
System.Linq.IQueryable
source
An System.Linq.IQueryable to return elements from. |
System.Int32
count
The number of elements to skip before returning the remaining elements. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable that contains elements that occur after the specified index in the input sequence. |
Exceptions
System.ArgumentNullException
|
Sort(IQueryable, IEnumerable<ISortDescriptor>)
Sorts the elements of a sequence using the specified sort descriptors.
Declaration
public static IQueryable Sort(this IQueryable source, IEnumerable<ISortDescriptor> sortDescriptors)
Parameters
System.Linq.IQueryable
source
A sequence of values to sort. |
System.Collections.Generic.IEnumerable<ISortDescriptor>
sortDescriptors
The sort descriptors used for sorting. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable whose elements are sorted according to a |
Sort(IQueryable, IEnumerable<SortDescriptor>)
Sorts the elements of a sequence using the specified sort descriptors.
Declaration
public static IQueryable Sort(this IQueryable source, IEnumerable<SortDescriptor> sortDescriptors)
Parameters
System.Linq.IQueryable
source
A sequence of values to sort. |
System.Collections.Generic.IEnumerable<SortDescriptor>
sortDescriptors
The sort descriptors used for sorting. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable whose elements are sorted according to a |
Sort(IQueryable, SortDescriptorCollection)
Sorts the elements of a sequence using the specified sort descriptors.
Declaration
public static IQueryable Sort(this IQueryable source, SortDescriptorCollection sortDescriptors)
Parameters
System.Linq.IQueryable
source
A sequence of values to sort. |
SortDescriptorCollection
sortDescriptors
The sort descriptors used for sorting. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable whose elements are sorted according to a |
Take(IQueryable, Int32)
Returns a specified number of contiguous elements from the start of a sequence.
Declaration
public static IQueryable Take(this IQueryable source, int count)
Parameters
System.Linq.IQueryable
source
The sequence to return elements from. |
System.Int32
count
The number of elements to return. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable that contains the specified number
of elements from the start of |
Exceptions
System.ArgumentNullException
|
ToIList(IQueryable)
Creates a System.Collections.Generic.IList<T> from an System.Linq.IQueryable where T is System.Linq.IQueryable.ElementType.
Declaration
public static IList ToIList(this IQueryable source)
Parameters
System.Linq.IQueryable
source
The System.Linq.IQueryable to create a System.Collections.Generic.List<T> from. |
Returns
System.Collections.IList
A System.Collections.Generic.List<T> that contains elements from the input sequence. |
Exceptions
System.ArgumentNullException
|
ToIList<T>(IQueryable<T>)
Creates a System.Collections.Generic.IList<T> from an System.Linq.IQueryable where T is System.Linq.IQueryable.ElementType.
Declaration
public static IList<T> ToIList<T>(this IQueryable<T> source)
Parameters
System.Linq.IQueryable<T>
source
The System.Linq.IQueryable to create a System.Collections.Generic.List<T> from. |
Returns
System.Collections.Generic.IList<T>
A System.Collections.Generic.List<T> that contains elements from the input sequence. |
Type Parameters
T
|
Exceptions
System.ArgumentNullException
|
Union(IQueryable, IQueryable)
Produces the set union of two sequences by using the default equality comparer.
Declaration
public static IQueryable Union(this IQueryable source1, IQueryable source2)
Parameters
System.Linq.IQueryable
source1
|
System.Linq.IQueryable
source2
|
Returns
System.Linq.IQueryable
|
Where(IQueryable, IEnumerable<IFilterDescriptor>)
Filters a sequence of values based on a collection of IFilterDescriptor.
Declaration
public static IQueryable Where(this IQueryable source, IEnumerable<IFilterDescriptor> filterDescriptors)
Parameters
System.Linq.IQueryable
source
The source. |
System.Collections.Generic.IEnumerable<IFilterDescriptor>
filterDescriptors
The filter descriptors. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable that contains elements from the input sequence
that satisfy the conditions specified by each filter descriptor in |
Where(IQueryable, Expression)
Filters a sequence of values based on a predicate.
Declaration
public static IQueryable Where(this IQueryable source, Expression predicate)
Parameters
System.Linq.IQueryable
source
An System.Linq.IQueryable to filter. |
System.Linq.Expressions.Expression
predicate
A function to test each element for a condition. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable that contains elements from the input sequence
that satisfy the condition specified by |
Where(IQueryable, CompositeFilterDescriptorCollection)
Filters a sequence of values based on a CompositeFilterDescriptorCollection.
Declaration
public static IQueryable Where(this IQueryable source, CompositeFilterDescriptorCollection filterDescriptors)
Parameters
System.Linq.IQueryable
source
The source. |
CompositeFilterDescriptorCollection
filterDescriptors
The composite filter descriptor collection. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable that contains elements from the input sequence
that satisfy the conditions specified by the |
Where(IQueryable, FilterDescriptorCollection)
Filters a sequence of values based on a collection of IFilterDescriptor.
Declaration
public static IQueryable Where(this IQueryable source, FilterDescriptorCollection filterDescriptors)
Parameters
System.Linq.IQueryable
source
The source. |
FilterDescriptorCollection
filterDescriptors
The filter descriptors. |
Returns
System.Linq.IQueryable
An System.Linq.IQueryable that contains elements from the input sequence
that satisfy the conditions specified by each filter descriptor in |