blog ; c# -- Npgsql 이용하여 postgresql 접속한후 데이터 가져오기

pg_test.cs

using System;
using Npgsql;

namespace npgsql_test
{
    class Program
    {
        static void Main(string[] args)
        {

            using (var conn = new NpgsqlConnection("Host=localhost;Username=postgres;Password=1234;Database=test2db"))
            {
                try
                {
                    conn.Open();
                    using (var cmd = new NpgsqlCommand())
                    {
                        cmd.Connection = conn;

                        cmd.CommandText = "select * from addresses";

                        using (var reader = cmd.ExecuteReader())
                        {
                            Console.WriteLine("table column 수 = {0} 개", reader.FieldCount); 

                            while (reader.Read())
                            {
                                // 각각의 항목 읽어 들이는 방법들...
                                // Console.WriteLine(reader.GetString(0));
                                // Console.WriteLine(reader.GetValue(3));
                                // Console.WriteLine(reader["email_address"] as string);

                                var data = new string[] { reader["id"].ToString(),
                                reader["email_address"].ToString(),
                                reader["user_id"].ToString(),
                                reader["createtime"].ToString() };

                                foreach (var x in data)
                                {
                                    Console.Write(x);
                                    Console.Write(" -- ");
                                }
                                Console.WriteLine();
                            }
                        }
                    }
                }
                catch (Exception ex)
                {
                    Console.WriteLine("============== Error ==============");
                    Console.WriteLine(ex.Message);
                }
            }

            Console.ReadLine();

        }
    }
}