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Cannot Create An Instance Of The Interface Iqueryable


There are actually two sides to the LINQ story: the consumer side and the implementer side. Varying the number of locations does not change the syntax of the query. Thus, your code needs to look like this: IUser user = new User(); This instantiates an instance of the User class (which provides the implementation), and assigns it to an object The Add Service Reference dialog box opens. Source

I'll add a tautological statement as well: the broader the support for the LINQ API, the better it is. LISTING 2 Trivial query AST, as generated by NRefactory • FromClause=QueryExpressionFromClause o Identifier=user o InExpression IdentifierExpression Identifier=users o MiddleClauses QueryExpressionWhereClause Condition BinaryOperatorExpression Left MemberReferenceExpression TargetObject c# .net entity-framework share|improve this question edited Nov 9 '15 at 3:56 Jamal♦ 28.5k10106213 asked Oct 24 '11 at 8:39 Naor 2071410 1 Is there any way you can shorten Aug 23, 2010 Is there option to convert from Linq.IQueryable to DataTable with some sort of CopyToDataTable() function. http://stackoverflow.com/questions/14993048/instantiate-empty-iqueryable-for-use-with-linq-to-sql

Create Iqueryable From List

Add the following using statements (Imports statement in Visual Basic) to the Program.cs (or Module1.vb in Visual Basic) file: C# Copy using System; using System.Linq; using LinqToTerraServerProvider; VB Copy Imports LinqToTerraServerProvider In Where(x => x.IsDeleted == false). That said, there are actually many operations that we cannot support. The problem is, for the most part, we are not running on small data sets or in memory.

In addition, VehicleTransmission holds reference of Vehicle and therefore MyApp.Domain.Transmission contains reference of MyApp.Domain.Company. I cant see the benefits of half the stuff, yet or ever. –ppumkin Feb 11 '15 at 22:26 add a comment| 3 Answers 3 active oldest votes up vote 12 down ToList() won't fix anything here. 2. Iqueryable In C# Example or just div or span tag can do this.i am using jsp/java servlet to do guestbook, but i had no idea to build the guestbook, so leave msg here.

NodeType : ExpressionType : "Equal" f. Reply tvb2727 Participant 895 Points 2386 Posts Re: How to instantiate IQueryable() in C# Dec 14, 2014 10:41 PM|tvb2727|LINK Thanks akhilrajau for your response. LocationFinder lf = new LocationFinder(lambdaExpression.Body); List locations = lf.Locations; if (locations.Count == 0) throw new InvalidQueryException("You must specify at least one place name in your query."); // Call the Web service and IUser user = new User(); share|improve this answer answered Jul 7 '11 at 13:36 Erkan Haspulat 6,69842547 add a comment| Your Answer draft saved draft discarded Sign up or log

Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count). Cannot Create An Instance Of The Abstract Class Or Interface C# By whichGroup == ALL I needed to query for whichGroup = anything, but I don't know how to do that in SQL. –user2073077 Feb 21 '13 at 2:43 @user2073077 Where(x => x.IsDeleted == false); if (vehicleNumber != null) { query = query.Where(x => x.VehicleNumber.Contains(vehicleNumber)); } return query.OrderBy(x => x.VehicleNumber); } public IEnumerable Get(Guid companyId, bool? In this method, it replaces the object that the innermost standard query operator call is applied to with a concrete list of Place objects.

Add Item To Iqueryable C#

In each and every case, the process was extremely painful. see here For example searching for john on name field to returen johnson, johns etc.I'm trying to override the IQueryable GetQueryable(IQueryable source) method on the QueryableFilterUserControl class. Create Iqueryable From List vehicleId) { VehicleId = vehicleId; } //Possibility to set vehicle that is not exists on the db public void SetVehicleNumber(string vehicleNumber) { VehicleId = null; VehicleNumber = vehicleNumber; } } public Declare Iqueryable Anonymous Type When building RavenLight's LINQ provider, we made the following assumptions: • All the data is available locally. • The total amount of the data in the data store is likely to

Knowing that a piece of equipment is " a device with a power switch" would allow one to do some operations with it (i.e. this contact form As I mentioned, I had the chance to build a few LINQ providers. Note The LINQ provider that this walkthrough creates is available as a sample. That is more or less what we have done. C# Instantiate Iqueryable

Because all the data is available locally and the amount of data stored is small, we are actually going to run queries directly against the data store. If I set the query var inside the IF statement then it tells me that the var doesn't exist in context when I try to loop through it. What we would get is actually something called transparent identifier, and we would have to track down from where it originated. have a peek here Mar 25, 2011 I'm staring to learn T4 .I want to create a framework for my self that enable me to generate DAL and UI.Like Code generator softwares that maps Codes

Users get to use LINQ, with all the benefits associated with it (strong typing and intelligence among the most important), but we don't have to tackle the entire complexity involved in Empty Iqueryable Where(x => x.CompanyId == companyId). In many cases, it literally doesn't pay to try to provide a LINQ provider abstraction on top of highly limited querying capabilities.

However, the target property is the response class which wraps the target property itself.

This functionality is handled elsewhere because it is specific to the data source being queried, whereas the code in this class is generic to any LINQ provider. Assume you have a logical UOW that makes three calls to separate services. C#VB Copy using System; using System.Collections.Generic; using System.Linq.Expressions; namespace LinqToTerraServerProvider { public static class Evaluator { ///

  /// Performs evaluation & replacement of independent sub-trees  ///   /// The root of Cannot Create An Instance Of An Interface Mvc I also allow my Unit Of Work scope to be a bit more flexible and let the consuming application define the beginning and end of the unit of work.

When running on a small data set in memory, it also performs beautifully. Consider this simple LINQ query: from user in users where user.Id == 1 select user; Though this is probably the very simplest LINQ query possible, the compiler translates it to something That is not the case with other LINQ implementations, since it is the IQueryable implementation that determines which operations are supported and which are not. Check This Out asked 5 years ago viewed 40313 times active 12 months ago Get the weekly newsletter!

Hot Network Questions Why put a warning sticker over the warning on this product? C#VB Copy using System; using System.Collections.Generic; using System.Linq; using System.Linq.Expressions; namespace LinqToTerraServerProvider { public class QueryableTerraServerData : IOrderedQueryable { #region Constructors ///

  /// This constructor is called by the client to Testing the LINQ Provider You can test your LINQ provider by creating a client application that contains a LINQ query against your data source. Finally, it replaces the sub-tree with a new node that represents a constant value.

The node is reconstructed because one of the arguments has changed (that is, the data source that it is applied to). Mar 27, 2011 I am implementing paging in my GridView. I'm the Creator a InKnowWorks and I have been working on a LINQ-based OWL/RDF DSL and language processing sub-systems for our Ontology (triple-store) database. Name : String : "user" b.

Type : Type : "Boolean" i. Holds references to all other projects. lambdaExpression = (LambdaExpression)Evaluator.PartialEval(lambdaExpression); // Get the place name(s) to query the Web service with. Just a current client insists on using it ALL and its doing my head in. –ppumkin Feb 11 '15 at 22:20 add a comment| protected by syb0rg Mar 1 '14 at

This approach has some limitations, but we actually left the option open to sit down at a later date and implement a LINQ provider that doesn't perform a linear scan operation Because I've wrapped my code in a using block, once execution is complete, it is automatically disposed. For developers who aren't well versed in compiler theory, this is a big stumbling block. You can throw an exception if you don't understand the query, of course, but that means that users will discover unsupported scenarios only at runtime, defeating much of the point of