<prompt> Tengeneza programu ya C inayoingiliana na hifadhidata ya PostgreSQL ili kuhifadhi na kudhibiti mfumo rahisi wa hesabu. Programu inapaswa kusaidia kuongeza vipengee, kusasisha idadi ya bidhaa, na kuonyesha orodha ya sasa.PLINFORMAT  <response>: kutumia Mfumo;kutumia Npgsql;nafasi ya jina InventorySystem Programu ya darasa private const string ConnectionString Hostlocalhost;Jina la mtumiajipostgres;Nenosirineno_la_siri_yako; Hifadhidatahesabu_db; tuli utupu Mainstring args AddItemLaptop, 10; AddItemMonitor, 5; DisplayInventory; UpdateItemQuantity1, 8; DisplayInventory; faragha tuli NpgsqlConnection GetConnection rudisha NpgsqlConnection mpya ConnectionString; utupu tuli wa kibinafsi AddItemjina la kamba, wingi wa int kutumia var connection GetConnection muunganisho.Fungua; kutumia var command new NpgsqlCommandINGIZA vitu jina, kiasi THAMANI name, quantity, muunganisho amri.Parameters.AddWithValuejina, jina; amri.Parameters.AddWithValuewingi, wingi; amri.ExecuteNonQuery; utupu tuli wa kibinafsi UpdateItemQuantitykitambulisho cha int, int newQuantity kutumia var connection GetConnection muunganisho.Fungua; kutumia var command new NpgsqlCommandSASISHA vitu WEKA wingi quantity WAPI id id, muunganisho amri.Parameters.AddWithValueid, id; amri.Parameters.AddWithValuequantity, newQuantty; amri.ExecuteNonQuery; Utupu tuli wa kibinafsi DisplayInventory kutumia var connection GetConnection muunganisho.Fungua; kutumia var amri NpgsqlCommand mpya CHAGUA KUTOKA vitu, unganisho kutumia var reader command.ExecuteReader Console.WriteLineIDtNametQuantity; wakati msomaji.Soma Console.WriteLinereader.GetInt320treader.GetString1treader.GetInt322; 