WinRT, Code First - query with Count()
Printed From: IdeaBlade
Category: DevForce
Forum Name: DevForce 2012
Forum Discription: For .NET 4.5
URL: http://www.ideablade.com/forum/forum_posts.asp?TID=4251
Printed Date: 24-Oct-2025 at 2:41pm
Topic: WinRT, Code First - query with Count()
Posted By: zbig
Subject: WinRT, Code First - query with Count()
Date Posted: 27-Jul-2013 at 2:10pm
Hi,
WinRT, DevForce 7.2, EF Code First.
I would like to retrieve the number of my entities (let say Users), but very simple query code with Count() extension gives compile error message 'cannot convert from 'int' to 'IdeaBlade.EntityModel.IEntityQuery':
var usersQuery = appTestEntityManager.Users.Count();
var result = await appTestEntityManager.ExecuteQueryAsync(usersQuery);
How to get a number of Users without retrieving the whole set of Users to the client?
Thanks in advance for any advice.
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Replies:
Posted By: kimj
Date Posted: 28-Jul-2013 at 9:32am
"Count" is a scalar query operator and will return the integer value, not a query. You can use the DevForce AsScalarAsync method to turn this into an actual query which can be awaited, eg:
var result = await appTestEntityManager.Users.AsScalarAsync().Count();
More information here - http://drc.ideablade.com/devforce-2012/bin/view/Documentation/async-immediate-execution - http://drc.ideablade.com/devforce-2012/bin/view/Documentation/async-immediate-execution .
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