If multi-update partly failed what I have to return from server?

Let's say if I update 5 records: 3 successful and 2 unsuccessful, what format of record-set should be returned from server? I.e. how to combine:

{
    "data": [
        {
            "DT_RowId":   "row_29",
            "first_name": "Fiona",
            "last_name":  "Green",
            "position":   "Chief Operating Officer (COO)",
            "office":     "San Francisco",
            "extn":       "2947",
            "salary":     "850000",
            "start_date": "2010-03-11"
        }
    ]
}

and

{
    "fieldErrors": [
        {
            "name":   "first_name",
            "status": "This field is required"
        },
        {
            "name":   "last_name",
            "status": "This field is required"
        }
    ]
}