CODEWITHSUNDEEP
c#linqentity-framework
razeth01
razeth01

Reputation: 638

Linq with entity framework

I'm new to LINQ and Entity Framework and would appreciate some advice on the following scenario.

I have a entity model with two tables.

Travel_Request and Resource

Sample Fields

Travel_Request

Request_ID
Resource_ID

Resource

Resource_ID
Resource_Name

I would like to add the Resource_Name to the list when returning all the TRAVEL_REQUESTS

Thanks in advance

Upvotes: 3

Views: 27805

Answers (5)

Michael90
Michael90

Reputation: 367

Use the Join:

Travel_Request.Join(Resource, tr => tr.ResourceId, r => r.ResourceId, (tr, r) => new { RequestId = tr.RequestId, ResourceId = tr.ResourceId, Name = r.ResourceName})

Or what a better practice would be is adding a Navigation property to TravelRequest. TravelRequest would look like this:

int RequestId { get; set; }
int ResourceId{ get; set; }
[ForeignKey("ResourceId")]
Resource Resource { get; set; }

This way you can use Include 

DBContext.TravelRequests.Include("Resource").First().Resource.Name;

Include tells EF to get the Resource with the TravelerRequest

Upvotes: 1

Fabien
Fabien

Reputation: 1105

Hi you need to use the Linq join:

var data = from t in Travel_Request
       join r in Resource on t.Resource_ID equals r.Resource_ID
       select new 
              { 
                 RequestId = t.Request_ID,
                 ResourceId = t.Resource_ID,
                 ResourceName = r.Resource_Name
              };

If you already have an EF association then it could simply be:

var data = from t in Travel_Request
    select new
           {
                 RequestId = t.Request_ID,
                 ResourceId = t.Resource_ID,
                 ResourceName = t.Resource.Resource_Name
           };

Upvotes: 7

Ryan Schlueter
Ryan Schlueter

Reputation: 2221

I would add a model that has all three then do something like. 

var TravelRequests = 
    from p in Travel_Request
from r in Resource.where(Res => Res.Resource_ID == p.Resource_ID)
    select new TravelModel{
requestID = p.requestID,
Resource_ID = p.Resource_ID,
ResourceName = r.ResourceName

};

But thats just an example of how I would do it and there might be better ways. Also syntax might be a little off but general idea is there.

Upvotes: 1

Thilina H
Thilina H

Reputation: 5812

You can query Travel_Request entity and use the navigation propety to do that.

var resultList = DbContext.Travel_Request.Resources.where(x=>x.Resource_Name =="Your string").ToList();

Upvotes: 1

Rob White
Rob White

Reputation: 1002

You will have to create a new object something like this.

var data = Travel_Request.Select(s=> new { Resource_Name = s.Recource.Resource_Name, Request_ID = s.Request_ID, Resource_ID = s.Resource_ID}).ToList();

As long as I've understood the question correctly this will work.

Upvotes: 2

Related Questions