Query from multiple tables

Question

We started working with the ADO.NET Entity Data Model Template and we like it a lot. We are having some trouble with the queries though. How do we do a query from multiple tables so it would return a single result and then show the result in a DataGrid? We're working in C# and Windows Forms.

ramesh p · Answer

Please try like this... gvIncidents.DataSource = from i in db.Incidents from it in db.IncidentTypes where (i.IncidentTypeId == it.IncidentTypeId) orderby i.IncidentId descending select new { IncidentId = i.IncidentId DateEntered = i.DateEntered EnteredBy = i.EnteredBy SchoolId = i.SchoolId CallerName = i.CallerName ParentIds = i.ParentIds StudentIds = i.StudentIds IncidentTypeName = it.IncidentTypeName };

NeCroFire · Answer

I got it working. Read here if there is anyone else having trouble with running and Entity model as a separate project/Data Layer. Just look for my name. http://social.msdn.microsoft.com/Forums/en-US/adodotnetentityframework/thread/d0261818-ed96-43b6-adfd-3c146d8e1a68?prof=required Cheers

NeCroFire · Answer

OK. Read through the blog and I think my problem might be the first he mentions: Your source is not enumerable! I don't follow what he means here. I made my Entity model as straight forward as possible but I'm guessing that's the problem. What exactly do I need to change or redo to get my source Enumerable?? And if it's just a property where do I change it?

Niradhip Chakraborty · Answer

For that particular error you can refer the following solution. http://blogs.interakting.co.uk/mattnield/archive/2008/01/25/LINQ-Error-19-Could-not-find-an-implementation-of-the.aspx

NeCroFire · Answer

I tried the query above but I'm getting this error msg; The specified named connection is either not found in the configuration not intended to be used with the EntityClient provider or not valid. I have created a separate project where I have added the the entity model and compiled it to a dll. Then I'm referencing the dll from my Service level. The error came up in the My_Entities.Designer.cs file.