Class XPQueryExtensions

Namespace

DevExpress.Xpo

Assembly

DevExpress.Xpo.v24.1.dll

Provides extension methods to work with XPQuery<T> objects.

public static class XPQueryExtensions

Inheritance

object

XPQueryExtensions

Inherited Members

object.GetType()

object.MemberwiseClone()

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Methods

AllAsync<T>(IQueryable<T>, Expression<Func<T, bool>>, CancellationToken)

Asynchronously checks whether all objects in a selection meet specific requirements.

public static Task<bool> AllAsync<T>(this IQueryable<T> query, Expression<Func<T, bool>> predicate, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

predicate Expression<Func<T, bool>>

An expression which determines requirements persistent objects need to meet.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<bool>

A Task that returns true if all objects in a selection meet specific requirements. Otherwise, it returns false.

Type Parameters

T

AnyAsync<T>(IQueryable<T>, Expression<Func<T, bool>>, CancellationToken)

Asynchronously checks whether any object in a selection meets specific requirements.

public static Task<bool> AnyAsync<T>(this IQueryable<T> query, Expression<Func<T, bool>> predicate, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

predicate Expression<Func<T, bool>>

An expression which determines requirements persistent objects need to meet.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<bool>

A Task that returns true if any object in a selection meets specific requirements. Otherwise, it returns false.

Type Parameters

T

AnyAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously checks whether any objects exist in a selection.

public static Task<bool> AnyAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<bool>

A Task that returns true if any objects exist in a selection. Otherwise, it returns false.

Type Parameters

T

AverageAsync(IQueryable<decimal>, CancellationToken)

Asynchronously calculates an average of objects’ specific Int64 fields for a query.

public static Task<decimal> AverageAsync(this IQueryable<decimal> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<decimal>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<decimal>

A Task that returns an average of objects’ specific Int64 fields for a query.

AverageAsync(IQueryable<double>, CancellationToken)

Asynchronously calculates an average of objects’ specific Double fields for a query.

public static Task<double> AverageAsync(this IQueryable<double> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<double>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<double>

A Task that returns an average of objects’ specific Double fields for a query.

AverageAsync(IQueryable<int>, CancellationToken)

Asynchronously calculates an average of objects’ specific Int32 fields, for a query.

public static Task<double> AverageAsync(this IQueryable<int> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<int>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<double>

A Task that returns an average of objects’ specific Int32 fields for a query.

AverageAsync(IQueryable<long>, CancellationToken)

Asynchronously calculates an average of objects’ specific Int64 fields for a query.

public static Task<double> AverageAsync(this IQueryable<long> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<long>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<double>

A Task that returns an average of objects’ specific Int64 fields for a query.

AverageAsync(IQueryable<float>, CancellationToken)

Asynchronously calculates an average of objects’ specific Single fields for a query.

public static Task<float> AverageAsync(this IQueryable<float> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<float>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<float>

A Task that returns an average of objects’ specific Single fields for a query.

AverageAsync<T>(IQueryable<T>, Expression<Func<T, decimal>>, CancellationToken)

Asynchronously calculates an average of objects’ specific Decimal fields for a query. Uses a lambda expression to obtain values.

public static Task<decimal> AverageAsync<T>(this IQueryable<T> query, Expression<Func<T, decimal>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, decimal>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<decimal>

A Task that returns an average of objects’ specific Decimal fields for a query.

Type Parameters

T

AverageAsync<T>(IQueryable<T>, Expression<Func<T, double>>, CancellationToken)

Asynchronously calculates an average of objects’ specific Double fields for a query. Uses a lambda expression to obtain values.

public static Task<double> AverageAsync<T>(this IQueryable<T> query, Expression<Func<T, double>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, double>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<double>

A Task that returns an average of objects’ specific Double fields for a query.

Type Parameters

T

AverageAsync<T>(IQueryable<T>, Expression<Func<T, int>>, CancellationToken)

Asynchronously calculates an average of objects’ specific Int32 fields for a query. Uses a lambda expression to obtain values.

public static Task<double> AverageAsync<T>(this IQueryable<T> query, Expression<Func<T, int>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, int>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<double>

A Task that returns an average of objects’ specific Int32 fields for a query.

Type Parameters

T

AverageAsync<T>(IQueryable<T>, Expression<Func<T, long>>, CancellationToken)

Asynchronously calculates an average of objects’ specific Int64 fields for a query. Uses a lambda expression to obtain values.

public static Task<double> AverageAsync<T>(this IQueryable<T> query, Expression<Func<T, long>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, long>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<double>

A Task that returns an average of objects’ specific Int64 fields for a query.

Type Parameters

T

AverageAsync<T>(IQueryable<T>, Expression<Func<T, float>>, CancellationToken)

Asynchronously calculates an average of objects’ specific Decimal fields for a query. Uses a lambda expression to obtain values.

public static Task<float> AverageAsync<T>(this IQueryable<T> query, Expression<Func<T, float>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, float>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<float>

A Task that returns an average of objects’ specific Decimal fields for a query.

Type Parameters

T

CachedExpression<TSource, TResult>(IQueryable<TSource>, Func<IQueryable<TSource>, TResult>)

For internal use.

public static TResult CachedExpression<TSource, TResult>(this IQueryable<TSource> source, Func<IQueryable<TSource>, TResult> f)

Parameters

source IQueryable<TSource>

f Func<IQueryable<TSource>, TResult>

Returns

TResult

Type Parameters

TSource

TResult

CachedExpression<TSource, TArg1, TResult>(IQueryable<TSource>, Func<IQueryable<TSource>, TArg1, TResult>, TArg1)

For internal use.

public static TResult CachedExpression<TSource, TArg1, TResult>(this IQueryable<TSource> source, Func<IQueryable<TSource>, TArg1, TResult> f, TArg1 a1)

Parameters

source IQueryable<TSource>

f Func<IQueryable<TSource>, TArg1, TResult>

a1 TArg1

Returns

TResult

Type Parameters

TSource

TArg1

TResult

CachedExpression<TSource, TArg1, TArg2, TResult>(IQueryable<TSource>, Func<IQueryable<TSource>, TArg1, TArg2, TResult>, TArg1, TArg2)

For internal use.

public static TResult CachedExpression<TSource, TArg1, TArg2, TResult>(this IQueryable<TSource> source, Func<IQueryable<TSource>, TArg1, TArg2, TResult> f, TArg1 a1, TArg2 a2)

Parameters

source IQueryable<TSource>

f Func<IQueryable<TSource>, TArg1, TArg2, TResult>

a1 TArg1

a2 TArg2

Returns

TResult

Type Parameters

TSource

TArg1

TArg2

TResult

CachedExpression<TSource, TArg1, TArg2, TArg3, TResult>(IQueryable<TSource>, Func<IQueryable<TSource>, TArg1, TArg2, TArg3, TResult>, TArg1, TArg2, TArg3)

For internal use.

public static TResult CachedExpression<TSource, TArg1, TArg2, TArg3, TResult>(this IQueryable<TSource> source, Func<IQueryable<TSource>, TArg1, TArg2, TArg3, TResult> f, TArg1 a1, TArg2 a2, TArg3 a3)

Parameters

source IQueryable<TSource>

f Func<IQueryable<TSource>, TArg1, TArg2, TArg3, TResult>

a1 TArg1

a2 TArg2

a3 TArg3

Returns

TResult

Type Parameters

TSource

TArg1

TArg2

TArg3

TResult

CachedExpression<TSource, TArg1, TArg2, TArg3, TArg4, TResult>(IQueryable<TSource>, Func<IQueryable<TSource>, TArg1, TArg2, TArg3, TArg4, TResult>, TArg1, TArg2, TArg3, TArg4)

For internal use.

public static TResult CachedExpression<TSource, TArg1, TArg2, TArg3, TArg4, TResult>(this IQueryable<TSource> source, Func<IQueryable<TSource>, TArg1, TArg2, TArg3, TArg4, TResult> f, TArg1 a1, TArg2 a2, TArg3 a3, TArg4 a4)

Parameters

source IQueryable<TSource>

f Func<IQueryable<TSource>, TArg1, TArg2, TArg3, TArg4, TResult>

a1 TArg1

a2 TArg2

a3 TArg3

a4 TArg4

Returns

TResult

Type Parameters

TSource

TArg1

TArg2

TArg3

TArg4

TResult

CachedExpression<TSource, TArg1, TArg2, TArg3, TArg4, TArg5, TResult>(IQueryable<TSource>, Func<IQueryable<TSource>, TArg1, TArg2, TArg3, TArg4, TArg5, TResult>, TArg1, TArg2, TArg3, TArg4, TArg5)

For internal use.

public static TResult CachedExpression<TSource, TArg1, TArg2, TArg3, TArg4, TArg5, TResult>(this IQueryable<TSource> source, Func<IQueryable<TSource>, TArg1, TArg2, TArg3, TArg4, TArg5, TResult> f, TArg1 a1, TArg2 a2, TArg3 a3, TArg4 a4, TArg5 a5)

Parameters

source IQueryable<TSource>

f Func<IQueryable<TSource>, TArg1, TArg2, TArg3, TArg4, TArg5, TResult>

a1 TArg1

a2 TArg2

a3 TArg3

a4 TArg4

a5 TArg5

Returns

TResult

Type Parameters

TSource

TArg1

TArg2

TArg3

TArg4

TArg5

TResult

ContainsAsync<T>(IQueryable<T>, T, CancellationToken)

Asynchronously checks whether a specific object exists in a selection.

public static Task<bool> ContainsAsync<T>(this IQueryable<T> query, T item, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

item T

An object, which specifies a persistent object to be found in a selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<bool>

A Task that returns true if a specific object exists in a selection. Otherwise, it returns false.

Type Parameters

T

CountAsync<T>(IQueryable<T>, Expression<Func<T, bool>>, CancellationToken)

Asynchronously counts the number of objects that meet specific requirements in a specified selection.

public static Task<int> CountAsync<T>(this IQueryable<T> query, Expression<Func<T, bool>> predicate, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

predicate Expression<Func<T, bool>>

An expression which determines requirements persistent objects need to meet.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<int>

An Task that returns an Int32 value. This value demonstrates how many objects in a selection meet specific requirements.

Type Parameters

T

CountAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously counts the number of objects in a selection.

public static Task<int> CountAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<int>

An Task that returns an Int32 value. This value is how many objects a selection contains.

Type Parameters

T

CustomAggregateAsync<T>(IQueryable<T>, string, Expression<Func<T, object>>, CancellationToken)

public static Task<object> CustomAggregateAsync<T>(this IQueryable<T> query, string customAggregateName, Expression<Func<T, object>> argument, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

customAggregateName string

argument Expression<Func<T, object>>

cancellationToken CancellationToken

Returns

Task<object>

Type Parameters

T

CustomAggregateAsync<T>(IQueryable<T>, string, params Expression<Func<T, object>>[])

public static Task<object> CustomAggregateAsync<T>(this IQueryable<T> query, string customAggregateName, params Expression<Func<T, object>>[] arguments)

Parameters

query IQueryable<T>

customAggregateName string

arguments Expression<Func<T, object>>[]

Returns

Task<object>

Type Parameters

T

CustomAggregateAsync<T>(IQueryable<T>, string, Expression<Func<T, object>>[], CancellationToken)

public static Task<object> CustomAggregateAsync<T>(this IQueryable<T> query, string customAggregateName, Expression<Func<T, object>>[] arguments, CancellationToken cancellationToken)

Parameters

query IQueryable<T>

customAggregateName string

arguments Expression<Func<T, object>>[]

cancellationToken CancellationToken

Returns

Task<object>

Type Parameters

T

CustomAggregate<T>(IQueryable<T>, string, params Expression<Func<T, object>>[])

public static object CustomAggregate<T>(this IQueryable<T> query, string customAggregateName, params Expression<Func<T, object>>[] arguments)

Parameters

query IQueryable<T>

customAggregateName string

arguments Expression<Func<T, object>>[]

Returns

object

Type Parameters

T

ElementAtAsync<T>(IQueryable<T>, int, CancellationToken)

Asynchronously gets an object that has a specific index in a selection.

public static Task<T> ElementAtAsync<T>(this IQueryable<T> query, int index, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

index int

An Int32 value, which specifies a persistent object’s index.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns an object. This object has a specific index.

Type Parameters

T

ElementAtOrDefaultAsync<T>(IQueryable<T>, int, CancellationToken)

Asynchronously gets an object that has a specific index in a selection. If the index is not valid, returns a default value for <T>.

public static Task<T> ElementAtOrDefaultAsync<T>(this IQueryable<T> query, int index, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

index int

An Int32 value, which specifies a persistent object’s index.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns an object, if the index is valid, or a default value for <T> if the index is not valid.

Type Parameters

T

EnumerateAsync<T>(IQueryable<T>, AsyncEnumerateCallback)

Asynchronously enumerates a specified query and notifies upon completion.

public static void EnumerateAsync<T>(this IQueryable<T> query, XPQueryExtensions.AsyncEnumerateCallback callback)

Parameters

query IQueryable<T>

An XPQuery<T> to be enumerated.

callback XPQueryExtensions.AsyncEnumerateCallback

An AsyncEnumerateCallback delegate, which is a method to be called after all elements in the query are enumerated.

Type Parameters

T

EnumerateAsync<T>(IQueryable<T>, AsyncEnumerateCallback<T>)

Asynchronously enumerates a specified query and notifies upon completion.

public static void EnumerateAsync<T>(this IQueryable<T> query, XPQueryExtensions.AsyncEnumerateCallback<T> callback)

Parameters

query IQueryable<T>

An XPQuery<T> to be enumerated.

callback XPQueryExtensions.AsyncEnumerateCallback<T>

An AsyncEnumerateCallback<T> delegate, which is a method to be called after all elements in the query are enumerated.

Type Parameters

T

EnumerateAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously enumerates a specified query.

public static Task<IEnumerable<T>> EnumerateAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> to be enumerated.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<IEnumerable<T>>

A Task that returns a collection of enumerated objects.

Type Parameters

T

FirstAsync<T>(IQueryable<T>, Expression<Func<T, bool>>, CancellationToken)

Asynchronously gets the first object that meets specified requirements in a selection. Throws an exception for empty selections.

public static Task<T> FirstAsync<T>(this IQueryable<T> query, Expression<Func<T, bool>> predicate, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

predicate Expression<Func<T, bool>>

An expression which determines requirements the persistent object needs to meet.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns the first object to meet specified requirements in a selection.

Type Parameters

T

FirstAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously gets the first object in a selection. Throws an exception for empty selections.

public static Task<T> FirstAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns the first object in a selection.

Type Parameters

T

FirstOrDefaultAsync<T>(IQueryable<T>, Expression<Func<T, bool>>, CancellationToken)

Asynchronously gets the first object that meets specified requirements in a selection. If the selection is empty, returns a default value for <T>.

public static Task<T> FirstOrDefaultAsync<T>(this IQueryable<T> query, Expression<Func<T, bool>> predicate, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

predicate Expression<Func<T, bool>>

An expression which determines requirements the persistent object needs to meet.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns the first object to meet specified requirements in a selection or a default value for <T>.

Type Parameters

T

FirstOrDefaultAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously gets the first object in a selection. If the selection is empty, returns a default value for <T>.

public static Task<T> FirstOrDefaultAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns the first object in a selection or a a default value for <T>.

Type Parameters

T

LastAsync<T>(IQueryable<T>, Expression<Func<T, bool>>, CancellationToken)

Asynchronously gets the last object that meets specified requirements in a selection. Throws an exception for empty selections.

public static Task<T> LastAsync<T>(this IQueryable<T> query, Expression<Func<T, bool>> predicate, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

predicate Expression<Func<T, bool>>

An expression which determines requirements the persistent object needs to meet.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns the last object to meet specified requirements in a selection.

Type Parameters

T

LastAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously gets the last object in a selection. Throws an exception for empty selections.

public static Task<T> LastAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns the last object in a selection.

Type Parameters

T

LastOrDefaultAsync<T>(IQueryable<T>, Expression<Func<T, bool>>, CancellationToken)

Asynchronously gets the last object that meets specified requirements in a selection. If the selection is empty, returns a default value for <T>.

public static Task<T> LastOrDefaultAsync<T>(this IQueryable<T> query, Expression<Func<T, bool>> predicate, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

predicate Expression<Func<T, bool>>

An expression which determines requirements the persistent object needs to meet.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns the last object to meet specified requirements in a selection or a default value for <T>.

Type Parameters

T

LastOrDefaultAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously gets the last object in a selection. If the selection is empty, returns a default value for <T>.

public static Task<T> LastOrDefaultAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns the last object in a selection or a default value for <T>.

Type Parameters

T

LongCountAsync<T>(IQueryable<T>, Expression<Func<T, bool>>, CancellationToken)

Asynchronously counts the number of objects that meet specific requirements in a specified selection.

public static Task<long> LongCountAsync<T>(this IQueryable<T> query, Expression<Func<T, bool>> predicate, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

predicate Expression<Func<T, bool>>

An expression which determines requirements persistent objects need to meet.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<long>

An Task that returns an Int64 value. This value demonstrates how many objects in a selection meet specific requirements.

Type Parameters

T

LongCountAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously counts the number of objects in a selection.

public static Task<long> LongCountAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<long>

An Task that returns an Int64 value. This value demonstrates how many objects a selection contains.

Type Parameters

T

MaxAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously gets the maximum value from a specified query.

public static Task<T> MaxAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns a object. This object is the maximum value.

Type Parameters

T

MaxAsync<T, TResult>(IQueryable<T>, Expression<Func<T, TResult>>, CancellationToken)

Asynchronously gets the maximum value from a specified query. Uses a lambda expression to obtain values.

public static Task<TResult> MaxAsync<T, TResult>(this IQueryable<T> query, Expression<Func<T, TResult>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, TResult>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<TResult>

A Task that returns an object. This object is the maximum value.

Type Parameters

T

TResult

MinAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously gets the minimum value from a specified query.

public static Task<T> MinAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns an object. This object is the minimum value.

Type Parameters

T

MinAsync<T, TResult>(IQueryable<T>, Expression<Func<T, TResult>>, CancellationToken)

Asynchronously gets the minimum value from a specified query. Uses a lambda expression to obtain values.

public static Task<TResult> MinAsync<T, TResult>(this IQueryable<T> query, Expression<Func<T, TResult>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, TResult>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<TResult>

A Task that returns an object. This object is the minimum value.

Type Parameters

T

TResult

QueryInTransaction<T>(Session)

Creates a new XPQuery<T> instance with the InTransaction (XPQuery<T>.InTransaction) mode enabled, from a specified session’s scope.

public static XPQuery<T> QueryInTransaction<T>(this Session session)

Parameters

session Session

A Session object or its descendant, which instantiates an XPQuery<T>. The specified session is assigned to the XPQueryBase.Session property.

Returns

XPQuery<T>

An XPQuery<T> object, instantiated from the session‘s scope, with the InTransaction mode enabled.

Type Parameters

T

Query<T>(IDataLayer)

Creates a new XPQuery<T> instance from a specified session’s scope.

public static XPQuery<T> Query<T>(this IDataLayer layer)

Parameters

layer IDataLayer

An IDataLayer object specifying the data access layer.

Returns

XPQuery<T>

An XPQuery<T> object instantiated from the session‘s scope.

Type Parameters

T

Query<T>(Session)

Creates a new XPQuery<T> instance from a specified session’s scope.

public static XPQuery<T> Query<T>(this Session session)

Parameters

session Session

A Session object or its descendant, which instantiates an XPQuery<T>. The specified session is assigned to the XPQueryBase.Session property.

Returns

XPQuery<T>

An XPQuery<T> object instantiated from the session‘s scope.

Type Parameters

T

SingleAsync<T>(IQueryable<T>, Expression<Func<T, bool>>, CancellationToken)

Asynchronously gets the object from a selection if only one object in the selection meets the specified requirements. Otherwise, throws an exception.

public static Task<T> SingleAsync<T>(this IQueryable<T> query, Expression<Func<T, bool>> predicate, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

predicate Expression<Func<T, bool>>

An expression which determines requirements the persistent object needs to meet.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns one object if this is the only object in a selection to meet the specified requirements.

Type Parameters

T

SingleAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously gets the object from a selection if this selection has only one object. Otherwise, throws an exception.

public static Task<T> SingleAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns the only object in a selection.

Type Parameters

T

SingleOrDefaultAsync<T>(IQueryable<T>, Expression<Func<T, bool>>, CancellationToken)

Asynchronously gets the object from a selection if only one object in the selection meets the specified requirements. If the selection is empty, returns a default value for <T>.

If the selection has more than one of such elements, throws an exception.

public static Task<T> SingleOrDefaultAsync<T>(this IQueryable<T> query, Expression<Func<T, bool>> predicate, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

predicate Expression<Func<T, bool>>

An expression which determines requirements the persistent object needs to meet.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns that returns one object if this is the only object in a selection to meet the specified requirements.

Type Parameters

T

SingleOrDefaultAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously gets the only object in a selection. If the selection is empty, returns a default value for <T>. If the selection has more than one element, throws an exception.

public static Task<T> SingleOrDefaultAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a selection of persistent objects.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T>

A Task that returns the only object in a selection.

Type Parameters

T

SumAsync(IQueryable<decimal>, CancellationToken)

Asynchronously calculates a sum of objects’ specific Decimal fields for a query.

public static Task<decimal> SumAsync(this IQueryable<decimal> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<decimal>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<decimal>

A Task that returns a sum of objects’ specific Decimal fields for a query.

SumAsync(IQueryable<double>, CancellationToken)

Asynchronously calculates a sum of objects’ specific Double fields for a query.

public static Task<double> SumAsync(this IQueryable<double> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<double>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<double>

A Task that returns a sum of objects’ specific Double fields for a query.

SumAsync(IQueryable<int>, CancellationToken)

Asynchronously calculates a sum of objects’ specific Int32 fields for a query.

public static Task<int> SumAsync(this IQueryable<int> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<int>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<int>

A Task that returns a sum of objects’ specific Int32 fields for a query.

SumAsync(IQueryable<long>, CancellationToken)

Asynchronously calculates a sum of objects’ specific Int64 fields for a query.

public static Task<long> SumAsync(this IQueryable<long> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<long>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<long>

A Task that returns a sum of objects’ specific Int64 fields for a query.

SumAsync(IQueryable<decimal?>, CancellationToken)

Asynchronously calculates a sum of objects’ specific nullable Decimal fields for a query.

public static Task<decimal?> SumAsync(this IQueryable<decimal?> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<decimal?>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<decimal?>

A Task that returns a sum of objects’ specific nullable Decimal fields for a query.

SumAsync(IQueryable<double?>, CancellationToken)

Asynchronously calculates a sum of objects’ specific nullable Double fields for a query.

public static Task<double?> SumAsync(this IQueryable<double?> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<double?>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<double?>

A Task that returns a sum of objects’ specific nullable Double fields for a query.

SumAsync(IQueryable<int?>, CancellationToken)

Asynchronously calculates a sum of objects’ specific nullable Int32 fields for a query.

public static Task<int?> SumAsync(this IQueryable<int?> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<int?>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<int?>

A Task that returns a sum of objects’ specific nullable Int32 fields for a query.

SumAsync(IQueryable<long?>, CancellationToken)

Asynchronously calculates a sum of objects’ specific nullable Int64 fields for a query.

public static Task<long?> SumAsync(this IQueryable<long?> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<long?>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<long?>

A Task that returns a sum of objects’ specific nullable Int64 fields for a query.

SumAsync(IQueryable<float?>, CancellationToken)

Asynchronously calculates a sum of objects’ specific nullable Single fields for a query.

public static Task<float?> SumAsync(this IQueryable<float?> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<float?>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<float?>

A Task that returns a sum of objects’ specific nullable Single fields for a query.

SumAsync(IQueryable<float>, CancellationToken)

Asynchronously calculates a sum of objects’ specific Single fields for a query.

public static Task<float> SumAsync(this IQueryable<float> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<float>

An XPQuery<T> that specifies a persistent object selection.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<float>

A Task that returns a sum of objects’ specific Single fields for a query.

SumAsync<T>(IQueryable<T>, Expression<Func<T, decimal>>, CancellationToken)

Asynchronously calculates a sum of objects’ specific Int64 fields for a query. Uses a lambda expression to obtain values.

public static Task<decimal> SumAsync<T>(this IQueryable<T> query, Expression<Func<T, decimal>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, decimal>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<decimal>

A Task that returns a sum of objects’ specific Int64 fields for a query.

Type Parameters

T

SumAsync<T>(IQueryable<T>, Expression<Func<T, double>>, CancellationToken)

Asynchronously calculates a sum of objects’ specific Double fields for a query. Uses a lambda expression to obtain values.

public static Task<double> SumAsync<T>(this IQueryable<T> query, Expression<Func<T, double>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, double>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<double>

A Task that returns a sum of objects’ specific Double fields for a query.

Type Parameters

T

SumAsync<T>(IQueryable<T>, Expression<Func<T, int>>, CancellationToken)

Asynchronously calculates a sum of objects’ specific Int32 fields for a query. Uses a lambda expression to obtain values.

public static Task<int> SumAsync<T>(this IQueryable<T> query, Expression<Func<T, int>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, int>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<int>

A Task that returns a sum of objects’ specific Int32 fields for a query.

Type Parameters

T

SumAsync<T>(IQueryable<T>, Expression<Func<T, long>>, CancellationToken)

Asynchronously calculates a sum of objects’ specific Int64 fields, for a query. Uses a lambda expression to obtain values.

public static Task<long> SumAsync<T>(this IQueryable<T> query, Expression<Func<T, long>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, long>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<long>

A Task that returns a sum of objects’ specific Int64 fields, for a query.

Type Parameters

T

SumAsync<T>(IQueryable<T>, Expression<Func<T, decimal?>>, CancellationToken)

Asynchronously calculates a sum of objects’ specific nullable Decimal fields for a query. Uses a lambda expression to obtain values.

public static Task<decimal?> SumAsync<T>(this IQueryable<T> query, Expression<Func<T, decimal?>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, decimal?>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<decimal?>

A Task that returns a sum of objects’ specific nullable Decimal fields for a query.

Type Parameters

T

SumAsync<T>(IQueryable<T>, Expression<Func<T, double?>>, CancellationToken)

Asynchronously calculates a sum of objects’ specific nullable Double fields for a query. Uses a lambda expression to obtain values.

public static Task<double?> SumAsync<T>(this IQueryable<T> query, Expression<Func<T, double?>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> object that specifies a persistent object selection.

selector Expression<Func<T, double?>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<double?>

A Task that returns a sum of objects’ specific nullable Double fields for a query.

Type Parameters

T

SumAsync<T>(IQueryable<T>, Expression<Func<T, int?>>, CancellationToken)

Asynchronously calculates a sum of objects’ specific nullable Int32 fields for a query. Uses a lambda expression to obtain values.

public static Task<int?> SumAsync<T>(this IQueryable<T> query, Expression<Func<T, int?>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, int?>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<int?>

A Task that returns a sum of objects’ specific nullable Int32 fields for a query.

Type Parameters

T

SumAsync<T>(IQueryable<T>, Expression<Func<T, long?>>, CancellationToken)

Asynchronously calculates a sum of objects’ specific nullable Int64 fields for a query. Uses a lambda expression to obtain values.

public static Task<long?> SumAsync<T>(this IQueryable<T> query, Expression<Func<T, long?>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, long?>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<long?>

A Task that returns a sum of objects’ specific nullable Int64 fields for a query.

Type Parameters

T

SumAsync<T>(IQueryable<T>, Expression<Func<T, float?>>, CancellationToken)

Asynchronously calculates a sum of objects’ specific nullable Single fields for a query. Uses a lambda expression to obtain values.

public static Task<float?> SumAsync<T>(this IQueryable<T> query, Expression<Func<T, float?>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, float?>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<float?>

A Task that returns a sum of objects’ specific nullable Single fields for a query.

Type Parameters

T

SumAsync<T>(IQueryable<T>, Expression<Func<T, float>>, CancellationToken)

Asynchronously calculates a sum of objects’ specific Decimal fields for a query. Uses a lambda expression to obtain values.

public static Task<float> SumAsync<T>(this IQueryable<T> query, Expression<Func<T, float>> selector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> that specifies a persistent object selection.

selector Expression<Func<T, float>>

A lambda expression that gets a value from a persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<float>

A Task that returns a sum of objects’ specific Decimal fields for a query.

Type Parameters

T

ToArrayAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously enumerates all objects in a query and saves them to an array.

public static Task<T[]> ToArrayAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> to be enumerated.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<T[]>

A Task that returns an array of objects.

Type Parameters

T

ToDictionaryAsync<T, TKey>(IQueryable<T>, Func<T, TKey>, IEqualityComparer<TKey>, CancellationToken)

Asynchronously enumerates a query and uses a key selector and an element selector to construct a Dictionary<TKey,TValue>.

public static Task<Dictionary<TKey, T>> ToDictionaryAsync<T, TKey>(this IQueryable<T> query, Func<T, TKey> keySelector, IEqualityComparer<TKey> equalityComparer, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> to be enumerated.

keySelector Func<T, TKey>

A function that acquires each persistent object’s key.

equalityComparer IEqualityComparer<TKey>

A function that returns a result value for each persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<Dictionary<TKey, T>>

A Task that returns a Dictionary<TKey,TValue>.

Type Parameters

T

TKey

ToDictionaryAsync<T, TKey>(IQueryable<T>, Func<T, TKey>, CancellationToken)

Asynchronously enumerates a query and uses a key selector to construct a Dictionary<TKey,TValue>.

public static Task<Dictionary<TKey, T>> ToDictionaryAsync<T, TKey>(this IQueryable<T> query, Func<T, TKey> keySelector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> to be enumerated.

keySelector Func<T, TKey>

A function that acquires each persistent object’s key.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<Dictionary<TKey, T>>

A Task that returns a Dictionary<TKey,TValue>.

Type Parameters

T

TKey

ToDictionaryAsync<T, TKey, TElement>(IQueryable<T>, Func<T, TKey>, Func<T, TElement>, IEqualityComparer<TKey>, CancellationToken)

Asynchronously enumerates a query and uses a key selector, an element selector, and a comparer to construct a Dictionary<TKey,TValue>.

public static Task<Dictionary<TKey, TElement>> ToDictionaryAsync<T, TKey, TElement>(this IQueryable<T> query, Func<T, TKey> keySelector, Func<T, TElement> elementSelector, IEqualityComparer<TKey> equalityComparer, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> to be enumerated.

keySelector Func<T, TKey>

A function that acquires each persistent object’s key.

elementSelector Func<T, TElement>

A function that returns a result value for each persistent object.

equalityComparer IEqualityComparer<TKey>

An IEqualityComparer<T> object that compares keys created for persistent objects.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<Dictionary<TKey, TElement>>

A Task that returns a Dictionary<TKey,TValue>.

Type Parameters

T

TKey

TElement

ToDictionaryAsync<T, TKey, TElement>(IQueryable<T>, Func<T, TKey>, Func<T, TElement>, CancellationToken)

Asynchronously enumerates a query and uses a key selector and an element selector to construct a Dictionary<TKey,TValue>.

public static Task<Dictionary<TKey, TElement>> ToDictionaryAsync<T, TKey, TElement>(this IQueryable<T> query, Func<T, TKey> keySelector, Func<T, TElement> elementSelector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> to be enumerated.

keySelector Func<T, TKey>

An function that acquires each persistent object’s key.

elementSelector Func<T, TElement>

A function that returns a result value for each persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<Dictionary<TKey, TElement>>

A Task that returns a Dictionary<TKey,TValue>.

Type Parameters

T

TKey

TElement

ToListAsync<T>(IQueryable<T>, CancellationToken)

Asynchronously enumerates all elements in a query and saves them to a list.

public static Task<List<T>> ToListAsync<T>(this IQueryable<T> query, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> to be enumerated.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<List<T>>

A Task that returns a list of objects.

Type Parameters

T

ToLookupAsync<T, TKey>(IQueryable<T>, Func<T, TKey>, IEqualityComparer<TKey>, CancellationToken)

Asynchronously enumerates a query and uses a key selector and a comparer to construct a Lookup<TKey,TElement>.

public static Task<ILookup<TKey, T>> ToLookupAsync<T, TKey>(this IQueryable<T> query, Func<T, TKey> keySelector, IEqualityComparer<TKey> equalityComparer, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> to be enumerated.

keySelector Func<T, TKey>

A function that acquires each persistent object’s key.

equalityComparer IEqualityComparer<TKey>

A function that returns a result value for each persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<ILookup<TKey, T>>

A Task that returns a Lookup<TKey,TElement>.

Type Parameters

T

TKey

ToLookupAsync<T, TKey>(IQueryable<T>, Func<T, TKey>, CancellationToken)

Asynchronously enumerates a query and uses a key selector to construct a Lookup<TKey,TElement>.

public static Task<ILookup<TKey, T>> ToLookupAsync<T, TKey>(this IQueryable<T> query, Func<T, TKey> keySelector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> to be enumerated.

keySelector Func<T, TKey>

A function that acquires each persistent object’s key.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<ILookup<TKey, T>>

A Task that returns a Lookup<TKey,TElement>.

Type Parameters

T

TKey

ToLookupAsync<T, TKey, TElement>(IQueryable<T>, Func<T, TKey>, Func<T, TElement>, IEqualityComparer<TKey>, CancellationToken)

Asynchronously enumerates a query and uses a key selector, an element selector and an comparer to construct a Lookup<TKey,TElement>.

public static Task<ILookup<TKey, TElement>> ToLookupAsync<T, TKey, TElement>(this IQueryable<T> query, Func<T, TKey> keySelector, Func<T, TElement> elementSelector, IEqualityComparer<TKey> equalityComparer, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> to be enumerated.

keySelector Func<T, TKey>

A function that acquires each persistent object’s key.

elementSelector Func<T, TElement>

A function that returns a result value for each persistent object.

equalityComparer IEqualityComparer<TKey>

A function that returns a result value for each persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<ILookup<TKey, TElement>>

A Task that returns a Lookup<TKey,TElement>.

Type Parameters

T

TKey

TElement

ToLookupAsync<T, TKey, TElement>(IQueryable<T>, Func<T, TKey>, Func<T, TElement>, CancellationToken)

Asynchronously enumerates a query and uses a key selector and an element selector to construct a Lookup<TKey,TElement>.

public static Task<ILookup<TKey, TElement>> ToLookupAsync<T, TKey, TElement>(this IQueryable<T> query, Func<T, TKey> keySelector, Func<T, TElement> elementSelector, CancellationToken cancellationToken = default)

Parameters

query IQueryable<T>

An XPQuery<T> to be enumerated.

keySelector Func<T, TKey>

A function that acquires each persistent object’s key.

elementSelector Func<T, TElement>

A function that returns a result value for each persistent object.

cancellationToken CancellationToken

A CancellationToken object that delivers a cancellation notice to the running operation.

Returns

Task<ILookup<TKey, TElement>>

A Task that returns a Lookup<TKey,TElement>.

Type Parameters

T

TKey

TElement