updateFields method
Implementation
Future<int> updateFields(
/* Expression | ExpressionMaker<ModelType> */ where,
Map<String, dynamic> values) async {
if (where is ExpressionMaker<ModelType>) where = where(this);
final st = updater.where(where);
for (String key in values.keys) {
final f = fields[key];
if (f == null) throw Exception('Unknown field!');
st.set(f, values[key]);
}
return adapter.update(st);
}