public class PGDBHelper
    {

        public static string pgsqlConnection = ConfigurationManager.ConnectionStrings["pgsqlConnection"].ConnectionString.ToString();
        /// <summary>
        /// select查詢
        /// </summary>
        /// <param name="sql"></param>
        /// <returns>
 
</returns>
        public static DataSet PostgreTable(string sql)
        {
            DataSet ds = new DataSet();
            using (NpgsqlConnection conn = new NpgsqlConnection(pgsqlConnection))
            {

                conn.Open();
                NpgsqlCommand cmd = new NpgsqlCommand(sql, conn);
                NpgsqlDataAdapter sda = new
 
 NpgsqlDataAdapter(cmd);

                sda.Fill(ds);

            }

            return ds;
        }

        /// <summary>
        /// 執行sql返回是否成功
        /// </summary>
        /// <param name="?"></param>
        /// <returns></returns>
        public static bool PostgreExecuQuery
 
(string StrText)
        {
            bool bools = false;

            using (NpgsqlConnection conn = new NpgsqlConnection(pgsqlConnection))
            {
                conn.Open();
                NpgsqlCommand cmd = new NpgsqlCommand(StrText, conn);
                int n = cmd.ExecuteNonQuery();
                conn.Close();
                if (n > 0) bools = true;
                else bools = false;
            }

            return bools;
        }

        /// <summary>
        /// 執行sql返回字元
        /// </summary>
        /// <param name="strText"></param>
        /// <param name="pgsqlConnection"></param>
        /// <returns></returns>
        public static string GetpostgreExecuteScalar(string strText, string StrConnection)
        {
            using (NpgsqlConnection conn = new NpgsqlConnection(StrConnection))
            {
                conn.Open();
                NpgsqlCommand cmd = new NpgsqlCommand(strText, conn);
                string PostgreScalar = cmd.ExecuteScalar().ToString();
                if (PostgreScalar != null || !string.IsNullOrEmpty(PostgreScalar))
                    return PostgreScalar;
                else return null;
            }
        }
    }

下載兩個已經封裝好的dll類庫
Npgsql.dll
Mono.Security.dll

引用名稱空間
using Npgsql;

開始一段空間資料庫旅程