I'm trying to get list items from a SharePoint list with specific fields only. The list contains lookup fields to other lists and I need the LookupId only for these.

I know two cases to narrow down the returned fields.

The first is with CAML. I can use the LookupId="TRUE" option to suppress the LookupValue in this case, but the server returns other system fields (eg. Modified By, Created By, etc.) which I don't need to.

The second is using 'Include' in ClientContext.load method. In this case the server not sends the system fields but I don't know how to specify (if possible) to receive the LookupId only for lookup fields. I tried several versions in Include (project.id, projectId, project.lookupId, project.Inlude(id)) but none of them worked.

So, my question is: how to retrieve only specified fields of a SharePoint list with LookupIds only for lookup fields?

I'm trying to get list items from a SharePoint list with specific fields only. The list contains lookup fields to other lists and I need the LookupId only for these.

I know two cases to narrow down the returned fields.

The first is with CAML. I can use the LookupId="TRUE" option to suppress the LookupValue in this case, but the server returns other system fields (eg. Modified By, Created By, etc.) which I don't need to.

The second is using 'Include' in ClientContext.load method. In this case the server not sends the system fields but I don't know how to specify (if possible) to receive the LookupId only for lookup fields. I tried several versions in Include (project.id, projectId, project.lookupId, project.Inlude(id)) but none of them worked.

So, my question is: how to retrieve only specified fields of a SharePoint list with LookupIds only for lookup fields?

• javascript
• sharepoint

2 Answers 2

You were very close to archive the desired result, you need to bine two techniques in order to retrieve id part of lookup value as demonstrated below:

var ctx = SP.ClientContext.get_current();
var list = ctx.get_web().get_lists().getByTitle(listTitle);
var items = list.getItems(createLookupQuery('Project'));
ctx.load(items,'Include(Project)'); 
ctx.executeQueryAsync(
   function(){
       if(items.get_count() > 0){
           var item = items.getItemAtIndex(0);
           console.log(item.get_fieldValues()['Project'].get_lookupId());   
       }
   }, 
   function(sender,args)
   {
      console.log(args.get_message()); 
   });


function createLookupQuery(lookupFieldName){
      var qry = new SP.CamlQuery();
      qry.set_viewXml("<View><ViewFields><FieldRef Name='" + lookupFieldName + "' LookupId='TRUE' /></ViewFields></View>");
      return qry;
}   

• In CAML query we specify attribute LookupId='TRUE' to retrieve Id part of lookup field value
• since CAML query includes also system field values, we utilize SP.ClientContext.load method to return specific field value only

how to retrieve only specified fields of a SharePoint list with LookupIds only for lookup fields?

The question is a bit unclear, but assuming you want to fetch the lookup id, you can do as follows.

Suppose you've retrieved the SP.ListItem with JSOM and stored it in to a variable, your lookup field will be representeed by a SP.LookupFieldValue object.

You can access it from the retrieved item object as below.

var lookupFieldValue = item.get_item('FieldName');
var lookupId = lookupFieldValue.get_lookupId();