public string Update(int id, string name, int city_id, string phone)
{
School s = new School() { id = id, name = name, city_id = city_id, phone = phone };
bool result = _sd.Update(s);
return result.ToJSON();
}
public string Add(string name, int city_id, string phone)
{
School s = new School() { name = name, city_id = city_id, phone = phone };
bool result = _sd.Insert(s);
return result.ToJSON();
}