int pkFields = 0;
Iterator<Entry<String,JsonNode>> i = node.fields();
while (i.hasNext()) {
Entry<String,JsonNode> field = i.next();
if (field.getValue().isContainerNode()) {
throw new InvalidChildCollectionException(field.getKey());
} else if (field.getValue().isValueNode()) {
Column column = getColumn (context.table, field.getKey());
if (field.getValue().isNull()) {
context.allValues.put(column, null);
} else {