How to update a multiple lookup field in SharePoint Designer 2013 (REST API)

Question

I would like to update a multiple lookup field in SharePoint Designer 2013. OOTB this is not possible. In SharePoint Designer 2010 it was possible. Now I would like to do this with for example a REST API call in the SharePoint Designer 2013 workflow. How can I do this?

UPDATE:

I've tried first to make it work in JavaScript but it is not working yet. What am I doing wrong in this script?

<script src="https://code.jquery.com/jquery-1.11.1.min.js" type="text/javascript"></script><script type="text/javascript">

$(document).ready(function(){

$.ajax({
    url: "<siteUrl>/_api/web/lists/getByTitle('TestKH')/items(5)",
    type: "POST",
    contentType: "application/json;odata=verbose",
    data: JSON.stringify({
         '__metadata': {
            'type': 'SP.Data.TestKHListItem',
         },
         'SBSId': { "results": [1,2] }
    }),
    headers: { 
          "Accept": "application/json;odata=verbose",
          "X-RequestDigest" : $("#__REQUESTDIGEST").val(),
          "X-HTTP-Method": "PATCH",
           "If-Match": "*"
       },   
    success: function (data) {
        console.log("done");
    },
    error: function (err) {
        console.log(JSON.stringify(err));
    }
});
});
</script>​​

Answer 1

Not sure how to make the API call in SP Designer (it's a hassle!) but your data should be something like this:

'ColumnNameId': {"results": [59, 60] } 

Note that you need to add 'Id' to the column name. The results object contains an array of the IDs of the lookup items.

Answer 2

You can make API calls via the "Call HTTP Web Service" action available in SharePoint 2013 workflows. More information can be found here:

Working with Web Services in SharePoint Workflows using SharePoint Designer 2013

Answer 3

Use below code to update lookup column with multiple selection:

<script src="https://code.jquery.com/jquery-1.11.1.min.js" type="text/javascript"></script>

<script type="text/javascript">
    $(document).ready(function(){
        $.ajax({  
            url: _spPageContextInfo.webAbsoluteUrl + "/_api/web/lists/GetByTitle('TestKH')/items(5)",  
            type: "POST",  
            headers: {  
                "accept": "application/json;odata=verbose",  
                "content-Type": "application/json;odata=verbose",
                "X-RequestDigest": $("#__REQUESTDIGEST").val(),
                "IF-MATCH": "*",  
                "X-HTTP-Method": "MERGE"  
            },  
            data: JSON.stringify({
                    "__metadata": {
                        "type": "SP.Data.TestKHListItem",
                    },
                    "SBSId": { "results": [1,2] }
                }),    
            success: function(data) {  
                console.log("Updated successfully.");  
            },  
            error: function(error) {  
                console.log(JSON.stringify(error));  
            }  
        }); 
    });
</script>

Note: Make sure you are using correct internal name of your lookup column in data. You can get the internal name of your column by following this article: How to find the Internal name of columns in SharePoint Online?

For designer workflow part you can follow below blogs:

1. REST-API POST call using SharePoint designer workflow
2. SharePoint Designer 2013 Workflows and POST REST API