{"testEvents": [
        {
            "id": 113068,
            "name1": "test",
            "count": 15
        },
        {
            "id": 113069,
            "name1": "test1",
            "count": 15
        }
    ]
}

{"testEvents": [
        {
            "id": 113068,
            "name1": "test",
            "count": 15
        },
        {
            "id": 113069,
            "name1": "test1",
            "count": 15
        }
        ,
        {
            "id": 113070,
            "name1": "test2",
            "count": 18
        }
    ]
}

UPDATE table SET payload = payload ||'{"id":113070,"name1":"test2","count":18}';