Below is the sample of how to retrieve related entity’s field value using oData.
Let’s take a example ..suppose we want to retrieve some field value from SystemUser entity(User Name and EmployeeId) OnLoad of Account where OwnerId of Account is equal to SystemUserId of SystemUser entity.Write below code on OnLoad of Account entity.
var serverUrl=Xrm.Page.context.getServerUrl();
var ownerId=Xrm.Page.getAttribute(“ownerid”).getValue()[0].id;
var ownerGuid=ownerId.substring(1,ownerId.length-1);
var oDataQuery=serverUrl+”/xrmservices/2011/OrganizationData.svc/SystemUserSet?$select=DomainName,EmployeeId,ParentSystemUserId,AccessMode&$expand=user_accounts&$filter=SystemUserId eq guid'”+ownerGuid+”‘”;
$.ajax(
{
type: “GET”,
contentType: “application/json; charset=utf-8”,
datatype: “json”,
url: oDataQuery,
beforeSend: function(XMLHttpRequest)
{
XMLHttpRequest.setRequestHeader(“Accept”,”application/json”);
},
success: function(data, textStatus, XmlHttpRequest)
{
if(data != null && data.d != null && data.d !=null)
{
var users=data.d.results[0];
var userName=users.DomainName;
//Lookup Manager(ParentSystemUserId)
var managerName=users.ParentSystemUserId.Name;
var managerId= users.ParentSystemUserId.Id;
var managerType=users.ParentSystemUserId.LogicalName;
// OptionSet
var accessMode=users.AccessMode.Value // This will return integer value
var employeeId=users.EmployeeId;
alert(‘User Name : ‘+users.DomainName +’Employee Id :’ +users.EmployeeId);
}
},
error: function(XmlHttpRequest,textStatus,errorThrown)
{
alert(‘oData select failed ‘+ oDataQuery);
}
}
);
Note : don’t forget to load json2.js and jquery1.4.1.min.js framework on Account Form.
Hope it will help u.