Author: Nishant Rana

There are few ways we can make use of LINQ to write queries against CRM.

Using the early bound entity classes along with the generated service context

Use the CrmSvcUtil tool to generated the early bound entity classes and service context

CrmSvcUtil.exe /url:http://<serverName>/<organizationName>/XRMServices/2011/Organization.svc

/out:<outputFilename>.cs /username:<username> /password:<password> /domain:<domainName>

/namespace:<outputNamespace> /serviceContextName:<serviceContextName>

Uri organizationUri = new Uri("http://server/orgname/XRMServices/2011/Organization.svc");
 Uri homeRealmUri = null;</pre>
<pre> ClientCredentials credentials = new ClientCredentials();
 credentials.Windows.ClientCredential = new System.Net.NetworkCredential("username", "password", "domain");
 OrganizationServiceProxy orgProxy = new OrganizationServiceProxy(organizationUri, homeRealmUri, credentials, null);
 orgProxy.EnableProxyTypes();
 IOrganizationService _service = (IOrganizationService)orgProxy; 
 
 var xrmServiceContext = new XrmServiceContext(_service);
 // get all contact record that has first name as Hugh
 var lstContact = (from c in xrmServiceContext.ContactSet
 where c.FirstName == "Hugh"
 select c).ToList();
 foreach(var contact in lstContact)
 {
 MessageBox.Show(contact.FullName);
 }

Using Early bound entity classes and OrganizationServiceContext

Suppose we have the early bound entity classes but haven’t generated the service context. In this case we can use OrganizationServiceContext

var xrmServiceContext = new OrganizationServiceContext(_service);

var lstContact = (from c in xrmServiceContext.CreateQuery<Contact>()
 where c.FirstName == "Hugh"
 select c).ToList();

foreach (var contact in lstContact)
 {
 MessageBox.Show(contact.FullName);
 }

Using Late bound and OrganizationServiceContext

Suppose we are not generating the early bound classes and using late binding

  var xrmServiceContext = new OrganizationServiceContext(_service);

 var lstContact = (from c in xrmServiceContext.CreateQuery("contact")
 where c["firstname"] == "Hugh"
 select c).ToList();

 foreach (var contact in lstContact)
 {
 MessageBox.Show(contact["fullname"].ToString());
 }

Hope it helps..