Insert user field using REST API

Question

I have issue with my query to post item on test list, it returns 400 error. My list columns:

Title | user

Here is my body of json:

       const body: string = JSON.stringify({
      "__metadata": {
        "type": "SP.Data.TestInsertPersonListItem"
      },
      "Title": "test",
      "user": {
        "__metadata": {
          "type": "SP.Data.UserInfoItem"
        },
        "Id": 8,
      }
      });
    return this.props.spHttpClient.post(`tenant.com/sites/randomsite/_api/web/lists/getbytitle('TestInsertPerson')/items`,
      SPHttpClient.configurations.v1,
      {
        headers: {
          'Accept': 'application/json;odata=nometadata',
          'Content-type': 'application/json;odata=verbose',
          'odata-version': ''
        },
        body: body
      });
  })

and it returns 400 error with error:

A type named 'SP.Data.UserInfoItem' could not be resolved by the model. When a model is available, each type name must resolve to a valid type.

When I leave only Title it works as expected. Does anybody face similiar problem and deal with it ?

Answer 1

For the name of the user column use <ColumnInternalName><Id> i.e append Id at the end of the column internal name. The value should be user id (integer). In your case it should be userId: 8

Answer 2

I solve this, just have to check how it looks like in network debugger, jesus sharepoint. Here is solution:

const body: string = JSON.stringify({
  "__metadata": {
    "type": "SP.Data.TestInsertPersonListItem"
  },
  "Title": "this is bull..",
  "userStringId": "8"
});