Class QueryableExtensions

Provides extension methods to process DataSourceRequest.

Inheritance

System.Object

QueryableExtensions

Namespace: Telerik.DataSource.Extensions

Assembly: Telerik.DataSource.dll

Syntax

public static class QueryableExtensions : Object

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.

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 source is null.

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 source.

Exceptions

System.ArgumentNullException source is null.

System.ArgumentOutOfRangeException index is less than zero.

GroupBy(IQueryable, IEnumerable<GroupDescriptor>, Boolean)

Groups the elements of a sequence according to a specified groupDescriptors.

Declaration

public static IQueryable GroupBy(this IQueryable source, IEnumerable<GroupDescriptor> groupDescriptors, bool includeItems = true)

Parameters

System.Linq.IQueryable source An System.Linq.IQueryable whose elements to group.

System.Collections.Generic.IEnumerable<GroupDescriptor> groupDescriptors The group descriptors used for grouping.

System.Boolean includeItems

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`2 items, whose elements contains a sequence of objects and a key.

GroupBy(IQueryable, IQueryable, IEnumerable<GroupDescriptor>, Boolean)

Declaration

public static IQueryable GroupBy(this IQueryable source, IQueryable notPagedData, IEnumerable<GroupDescriptor> groupDescriptors, bool includeItems = true)

Parameters

System.Linq.IQueryable source

System.Linq.IQueryable notPagedData

System.Collections.Generic.IEnumerable<GroupDescriptor> groupDescriptors

System.Boolean includeItems

Returns

System.Linq.IQueryable

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, Nullable<ListSortDirection> sortDirection)

Parameters

System.Linq.IQueryable source The source.

System.Linq.Expressions.LambdaExpression keySelector The key selector.

System.Nullable<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 pageIndex.

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 source.

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 source is null.

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 sortDescriptors.

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 source.

Exceptions

System.ArgumentNullException source is null.

ToDataSourceResult(IEnumerable, DataSourceRequest)

Applies paging, sorting, filtering and grouping using the information from the DataSourceRequest object. If the collection is already paged, the method returns an empty result.

Declaration

public static DataSourceResult ToDataSourceResult(this IEnumerable enumerable, DataSourceRequest request)

Parameters

System.Collections.IEnumerable enumerable An instance of System.Collections.IEnumerable.

DataSourceRequest request An instance of DataSourceRequest.

Returns

DataSourceResult A DataSourceResult object, which contains the processed data after paging, sorting, filtering and grouping are applied.

ToDataSourceResult(DataTable, DataSourceRequest)

Applies paging, sorting, filtering and grouping using the information from the DataSourceRequest object. If the collection is already paged, the method returns an empty resullt.

Declaration

public static DataSourceResult ToDataSourceResult(this DataTable dataTable, DataSourceRequest request)

Parameters

System.Data.DataTable dataTable An instance of System.Data.DataTable.

DataSourceRequest request An instance of DataSourceRequest.

Returns

DataSourceResult A DataSourceResult object, which contains the processed data after paging, sorting, filtering and grouping are applied.

ToDataSourceResult(IQueryable, DataSourceRequest)

Applies paging, sorting, filtering and grouping using the information from the DataSourceRequest object. If the collection is already paged, the method returns an empty result.

Declaration

public static DataSourceResult ToDataSourceResult(this IQueryable queryable, DataSourceRequest request)

Parameters

System.Linq.IQueryable queryable An instance of System.Linq.IQueryable.

DataSourceRequest request An instance of DataSourceRequest.

Returns

DataSourceResult A DataSourceResult object, which contains the processed data after paging, sorting, filtering and grouping are applied.

ToDataSourceResult<TModel, TResult>(IEnumerable<TModel>, DataSourceRequest, Func<TModel, TResult>)

Declaration

public static DataSourceResult ToDataSourceResult<TModel, TResult>(this IEnumerable<TModel> enumerable, DataSourceRequest request, Func<TModel, TResult> selector)

Parameters

System.Collections.Generic.IEnumerable<TModel> enumerable

DataSourceRequest request

System.Func<TModel, TResult> selector

Returns

DataSourceResult

Type Parameters

TModel

TResult

ToDataSourceResult<TModel, TResult>(IQueryable<TModel>, DataSourceRequest, Func<TModel, TResult>)

Declaration

public static DataSourceResult ToDataSourceResult<TModel, TResult>(this IQueryable<TModel> enumerable, DataSourceRequest request, Func<TModel, TResult> selector)

Parameters

System.Linq.IQueryable<TModel> enumerable

DataSourceRequest request

System.Func<TModel, TResult> selector

Returns

DataSourceResult

Type Parameters

TModel

TResult

ToDataSourceResultAsync(IEnumerable, DataSourceRequest)

Applies paging, sorting, filtering and grouping using the information from the DataSourceRequest object. If the collection is already paged, the method returns an empty result.

Declaration

public static Task<DataSourceResult> ToDataSourceResultAsync(this IEnumerable enumerable, DataSourceRequest request)

Parameters

System.Collections.IEnumerable enumerable An instance of System.Collections.IEnumerable.

DataSourceRequest request An instance of DataSourceRequest.

Returns

System.Threading.Tasks.Task<DataSourceResult> A Task of DataSourceResult object, which contains the processed data after paging, sorting, filtering and grouping are applied. It can be called with the "await" keyword for asynchronous operation.

ToDataSourceResultAsync(DataTable, DataSourceRequest)

Applies paging, sorting, filtering and grouping using the information from the DataSourceRequest object. If the collection is already paged, the method returns an empty resullt.

Declaration

public static Task<DataSourceResult> ToDataSourceResultAsync(this DataTable dataTable, DataSourceRequest request)

Parameters

System.Data.DataTable dataTable An instance of System.Data.DataTable.

DataSourceRequest request An instance of DataSourceRequest.

Returns

System.Threading.Tasks.Task<DataSourceResult> A Task of DataSourceResult object, which contains the processed data after paging, sorting, filtering and grouping are applied. It can be called with the "await" keyword for asynchronous operation.

ToDataSourceResultAsync(IQueryable, DataSourceRequest)

Applies paging, sorting, filtering and grouping using the information from the DataSourceRequest object. If the collection is already paged, the method returns an empty result.

Declaration

public static Task<DataSourceResult> ToDataSourceResultAsync(this IQueryable queryable, DataSourceRequest request)

Parameters

System.Linq.IQueryable queryable An instance of System.Linq.IQueryable.

DataSourceRequest request An instance of DataSourceRequest.

Returns

System.Threading.Tasks.Task<DataSourceResult> A Task of DataSourceResult object, which contains the processed data after paging, sorting, filtering and grouping are applied. It can be called with the "await" keyword for asynchronous operation.

ToDataSourceResultAsync<TModel, TResult>(IEnumerable<TModel>, DataSourceRequest, Func<TModel, TResult>)

Declaration

public static Task<DataSourceResult> ToDataSourceResultAsync<TModel, TResult>(this IEnumerable<TModel> enumerable, DataSourceRequest request, Func<TModel, TResult> selector)

Parameters

System.Collections.Generic.IEnumerable<TModel> enumerable

DataSourceRequest request

System.Func<TModel, TResult> selector

Returns

System.Threading.Tasks.Task<DataSourceResult>

Type Parameters

TModel

TResult

ToDataSourceResultAsync<TModel, TResult>(IQueryable<TModel>, DataSourceRequest, Func<TModel, TResult>)

Declaration

public static Task<DataSourceResult> ToDataSourceResultAsync<TModel, TResult>(this IQueryable<TModel> queryable, DataSourceRequest request, Func<TModel, TResult> selector)

Parameters

System.Linq.IQueryable<TModel> queryable

DataSourceRequest request

System.Func<TModel, TResult> selector

Returns

System.Threading.Tasks.Task<DataSourceResult>

Type Parameters

TModel

TResult

Union(IQueryable, IQueryable)

Produces the set union of two sequences by using the default equality comparer.

Declaration

public static IQueryable Union(this IQueryable source, IQueryable second)

Parameters

System.Linq.IQueryable source An System.Linq.IQueryable whose distinct elements form the first set for the union.

System.Linq.IQueryable second An System.Linq.IQueryable whose distinct elements form the first set for the union.

Returns

System.Linq.IQueryable An System.Linq.IQueryable that contains the elements from both input sequences, excluding duplicates.

Exceptions

System.ArgumentNullException source is null.

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 filterDescriptors.

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 predicate.