public class XPQuery<T> :
    XPQueryBase,
    IOrderedQueryable<T>,
    IQueryable<T>,
    IEnumerable<T>,
    IEnumerable,
    IQueryable,
    IOrderedQueryable,
    IQueryProvider

Public Class XPQuery(Of T)
    Inherits XPQueryBase
    Implements IOrderedQueryable(Of T),
               IQueryable(Of T),
               IEnumerable(Of T),
               IEnumerable,
               IQueryable,
               IOrderedQueryable,
               IQueryProvider

C#
VB.NET

public class XPQuery<T> :
    XPQueryBase,
    IOrderedQueryable<T>,
    IEnumerable<T>,
    IEnumerable,
    IOrderedQueryable,
    IQueryable,
    IQueryable<T>,
    IQueryProvider

Public Class XPQuery(Of T)
    Inherits XPQueryBase
    Implements IOrderedQueryable(Of T),
               IEnumerable(Of T),
               IEnumerable,
               IOrderedQueryable,
               IQueryable,
               IQueryable(Of T),
               IQueryProvider

Type Parameters

Name	Description
T

Remarks

To execute LINQ queries for persistent objects, perform the following steps:

Create the XPQuery<T> instance of the required type.
Write the required LINQ queries for the created XPQuery<T> instance.

The following code snippet illustrates this. It prints the last names of all the customers named "John":

C#
VB.NET


using DevExpress.Xpo;

//...

Session MainSession = new Session();
XPQuery<Customer> customersQuery = new XPQuery<Customer>(MainSession);

var customers = from c in customersQuery
                where c.Name == "John"
                select c;

foreach (Customer customer in customers)
    Console.WriteLine(customer.LastName);


Imports DevExpress.Xpo

'...

Dim MainSession As New Session()
Dim customersQuery As XPQuery(Of Customer) = New XPQuery(Of Customer)(MainSession)

Dim customers = from c in customersQuery where c.Name = "John" select c

For Each customer As Customer In customers
    Console.WriteLine(customer.LastName)
Next customer

For more examples on using the XPQuery<T> class, refer to the LINQ to XPO knowledge base article.

XPO LINQ expressions are processed on the database server side and only the requested objects are loaded into the application.

Inheritance

Object

XPQueryBase

Extension Methods

DevExpress.Xpo.XPQueryExtensions.EnumerateAsync<T>(DevExpress.Xpo.XPQueryExtensions.AsyncEnumerateCallback<T>)

DevExpress.Xpo.XPQueryExtensions.EnumerateAsync<T>(DevExpress.Xpo.XPQueryExtensions.AsyncEnumerateCallback)

DevExpress.Xpo.XPQueryExtensions.EnumerateAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.CachedExpression<T, TResult>(Func<IQueryable<T>, TResult>)

DevExpress.Xpo.XPQueryExtensions.CachedExpression<T, TArg1, TResult>(Func<IQueryable<T>, TArg1, TResult>, TArg1)

DevExpress.Xpo.XPQueryExtensions.CachedExpression<T, TArg1, TArg2, TResult>(Func<IQueryable<T>, TArg1, TArg2, TResult>, TArg1, TArg2)

DevExpress.Xpo.XPQueryExtensions.CachedExpression<T, TArg1, TArg2, TArg3, TResult>(Func<IQueryable<T>, TArg1, TArg2, TArg3, TResult>, TArg1, TArg2, TArg3)

DevExpress.Xpo.XPQueryExtensions.CachedExpression<T, TArg1, TArg2, TArg3, TArg4, TResult>(Func<IQueryable<T>, TArg1, TArg2, TArg3, TArg4, TResult>, TArg1, TArg2, TArg3, TArg4)

DevExpress.Xpo.XPQueryExtensions.CachedExpression<T, TArg1, TArg2, TArg3, TArg4, TArg5, TResult>(Func<IQueryable<T>, TArg1, TArg2, TArg3, TArg4, TArg5, TResult>, TArg1, TArg2, TArg3, TArg4, TArg5)

DevExpress.Xpo.XPQueryExtensions.ToListAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.ToArrayAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.ToDictionaryAsync<T, TKey>(Func<T, TKey>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.ToDictionaryAsync<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>, IEqualityComparer<TKey>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.ToDictionaryAsync<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.ToDictionaryAsync<T, TKey>(Func<T, TKey>, IEqualityComparer<TKey>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.ToLookupAsync<T, TKey>(Func<T, TKey>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.ToLookupAsync<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.ToLookupAsync<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>, IEqualityComparer<TKey>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.ToLookupAsync<T, TKey>(Func<T, TKey>, IEqualityComparer<TKey>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.ElementAtAsync<T>(Int32, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.ElementAtOrDefaultAsync<T>(Int32, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.CountAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.CountAsync<T>(Expression<Func<T, Boolean>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.LongCountAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.LongCountAsync<T>(Expression<Func<T, Boolean>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.ContainsAsync<T>(T, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.AnyAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.AnyAsync<T>(Expression<Func<T, Boolean>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.AllAsync<T>(Expression<Func<T, Boolean>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.FirstAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.FirstAsync<T>(Expression<Func<T, Boolean>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.FirstOrDefaultAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.FirstOrDefaultAsync<T>(Expression<Func<T, Boolean>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.LastAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.LastAsync<T>(Expression<Func<T, Boolean>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.LastOrDefaultAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.LastOrDefaultAsync<T>(Expression<Func<T, Boolean>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SingleAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SingleAsync<T>(Expression<Func<T, Boolean>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SingleOrDefaultAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SingleOrDefaultAsync<T>(Expression<Func<T, Boolean>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.MinAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.MinAsync<T, TResult>(Expression<Func<T, TResult>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.MaxAsync<T>(CancellationToken)

DevExpress.Xpo.XPQueryExtensions.MaxAsync<T, TResult>(Expression<Func<T, TResult>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SumAsync<T>(Expression<Func<T, Int32>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SumAsync<T>(Expression<Func<T, Nullable<Int32>>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SumAsync<T>(Expression<Func<T, Int64>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SumAsync<T>(Expression<Func<T, Nullable<Int64>>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SumAsync<T>(Expression<Func<T, Decimal>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SumAsync<T>(Expression<Func<T, Nullable<Decimal>>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SumAsync<T>(Expression<Func<T, Single>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SumAsync<T>(Expression<Func<T, Nullable<Single>>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SumAsync<T>(Expression<Func<T, Double>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.SumAsync<T>(Expression<Func<T, Nullable<Double>>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.AverageAsync<T>(Expression<Func<T, Int32>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.AverageAsync<T>(Expression<Func<T, Int64>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.AverageAsync<T>(Expression<Func<T, Decimal>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.AverageAsync<T>(Expression<Func<T, Single>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.AverageAsync<T>(Expression<Func<T, Double>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.CustomAggregate<T>(String, Expression<Func<T, Object>>[])

DevExpress.Xpo.XPQueryExtensions.CustomAggregateAsync<T>(String, Expression<Func<T, Object>>[])

DevExpress.Xpo.XPQueryExtensions.CustomAggregateAsync<T>(String, Expression<Func<T, Object>>, CancellationToken)

DevExpress.Xpo.XPQueryExtensions.CustomAggregateAsync<T>(String, Expression<Func<T, Object>>[], CancellationToken)

General Information

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Quality Assurance and Productivity

Desktop

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Tools

Frameworks and Libraries

Web

Controls and Extensions

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Maintenance Mode

Mobile

Enterprise and Analytic Tools

End-User Documentation

General Information

.NET Subscription

Common Tools

Quality Assurance and Productivity

Desktop

Controls

Tools

Frameworks and Libraries

Web

Controls and Extensions

Tools

Maintenance Mode

Mobile

Enterprise and Analytic Tools

End-User Documentation

XPQuery<T> Class

Declaration

Type Parameters

Remarks

Inheritance

Extension Methods