Clear multi user fields in SharePoint Online using Power Automate with the REST API

I covered most types of fields previously but I didn’t cover the clear multi user field problem in SharePoint Online.

Clearing fields

A while back I wrote a post about clearing fields in Microsoft Flow. For details on how to update fields please look at the previous post.

Clear Multi user fields

I tried all sorts of ways but I kept hit all sorts of failures in my REST API call to SharePoint.

A collection of the errors that I saw:

An unexpected ‘StartObject’ node was found when reading from the JSON reader. A ‘PrimitiveValue’ node was expected.

A node of type ‘PrimitiveValue’ was read from the JSON reader when trying to read the contents of an entity set reference navigation link; however, a ‘StartObject’ or ‘StartArray’ node was expected.

A node of type ‘StartArray’ was read from the JSON reader when trying to read the contents of a resource reference navigation link; however, a ‘StartObject’ node or ‘PrimitiveValue’ node with null value was expected.

It was not until I looked at how to update a multi user field and then combined this with the how to reset a user field that I got to the solution. In my case I’ve got afield called CheckedBy.

The important bit in the above screenshot is the setting the Id to -1 and the StringId part of the field to an empty string.

'CheckedById': {
  '__metadata': {
    'type': 'Collection(Edm.Int32)'
  },
  'results': [
    -1
  ]
},
'CheckedByStringId': {
'__metadata': {
  'type': 'Collection(Edm.String)'
},
  'results': [
  '' ]
}

Ok, this is great, problem solved!