How to use SharePoint 2013 REST service to retrieve data from lookup field

Question

I have two lists: 'Company' and 'Customer'. In 'Customer', I have an auto look up field called 'parent'. Then I tried to use Rest to retrieve data from customer like this:

http://mysite/_api/web/lists/getByTitle('Customer')/items?$select=parent/Id&$expand=parent/Id

But the response returned error: <m:message xml:lang="en-US">The field or property 'parent' does not exist.</m:message>

What can I do to get rid of this error.

thanks in advanced

Answer 1

The syntax of your query seems correct. Most probably this error occurs since $select and $expand operators are case-sensitive.

Try the following query:

/_api/web/lists/getByTitle('Customer')/items?$select=Parent/Title&$expand=Parent 

Answer 2

You should use the internal name of the fields in the query. Check the internal name of the 'parent' field, for example via PowerShell:

$web = Get-SPWeb http://mysite
$list = $web.Lists["Customer"]
$list.Fields | % { $_.InternalName }

or via

http://mysite/_api/web/lists/getByTitle('Customer')/items

If the lookup field was renamed, it might have already a different title than you need.