C#Postgresql 帮助类 Helper

demo下载  https://download.csdn.net/download/qq_37935177/12558674

配置webconfig

<connectionStrings>
    <add name="postgre" connectionString="PORT=5432;DATABASE=utodb;HOST=192.168.1.1;PASSWORD=123456;USER ID=qq"/>
  </connectionStrings>

  public static string ConnectionString = ConfigurationManager.ConnectionStrings["postgre"].ToString();


        /// 

        /// 增 删 改， 无参
        /// 
        /// 
        /// 
        public static int ExecuteSQL(string sql) {
     
            int num2 = -1;
            using (NpgsqlConnection connection = new NpgsqlConnection(ConnectionString)) {
     
                using (NpgsqlCommand command = new NpgsqlCommand(sql, connection)) {
     
                    try {
     
                        connection.Open();
                        num2 = command.ExecuteNonQuery();
                    } catch (NpgsqlException exception) {
     
                        throw new Exception(exception.Message);
                    } finally {
     
                        connection.Close();
                    }
                }
            }
            return num2;
        }

       /// 

       /// 增 删 改
       /// 
       /// 
       /// 
       /// 
        public static int ExecuteNonQuery(string sql, params NpgsqlParameter[] parameters) {
     
            using (NpgsqlConnection conn = new NpgsqlConnection(ConnectionString)) {
     
                conn.Open();
                using (NpgsqlCommand cmd = conn.CreateCommand()) {
     
                    cmd.CommandText = sql;
                    //foreach (SqlParameter param in parameters)
                    //{
     
                    //    cmd.Parameters.Add(param);
                    //}
                    cmd.Parameters.AddRange(parameters);
                    return cmd.ExecuteNonQuery();
                }
            }
        }

        /// 

        /// 查询操作，返回查询结果中的第一行第一列的值
        /// 
        /// 
        /// 
        /// 
        public static object ExecuteScalar(string sql, params NpgsqlParameter[] parameters) {
     
            using (NpgsqlConnection conn = new NpgsqlConnection(ConnectionString)) {
     
                conn.Open();
                using (NpgsqlCommand cmd = conn.CreateCommand()) {
     
                    cmd.CommandText = sql;
                    cmd.Parameters.AddRange(parameters);
                    return cmd.ExecuteScalar();

                }
            }
        }




        /// 

        /// 查询并返回结果集DataTable
        /// 
        /// 
        /// 
        /// 
        public static DataTable ExecuteDataTable(string sql, params NpgsqlParameter[] parameters) {
     
            using (NpgsqlConnection conn = new NpgsqlConnection(ConnectionString)) {
     
                conn.Open();
                using (NpgsqlCommand cmd = conn.CreateCommand()) {
     
                    cmd.CommandText = sql;
                    if (parameters!=null) {
     
                        cmd.Parameters.AddRange(parameters);
                    }

                    NpgsqlDataAdapter adapter = new NpgsqlDataAdapter(cmd);
                    DataSet dataset = new DataSet();
                    adapter.Fill(dataset);
                    return dataset.Tables[0];
                }
            }

        }

新建一个控制台程序 ，应该需要添加nuget包

  static void Main(string[] args) {
     

            
            //DataTable dt = pghelper.ExecuteDataTable("select modifiedtime from jbxx", null);
            //if (dt.Rows.Count > 0) {
     
            //    Console.WriteLine(dt.Rows[0]["modifiedtime"].ToString().Trim());
            //}

            //string str=   pghelper.ExecuteScalar("select modifiedtime from jbxx").ToString().Trim();
            //   Console.WriteLine(str);

            //  int a = pghelper.ExecuteNonQuery("update jbxx set modifiedtime=@modifiedtime,jbxx_lx=@lx", new NpgsqlParameter("@modifiedtime", System.DateTime.Now), new NpgsqlParameter("@lx", "2"));

            NpgsqlParameter[] pms = new NpgsqlParameter[] {
     
                 new NpgsqlParameter("@modifiedtime",NpgsqlDbType.Date,20){
      Value =System.DateTime.Now},
                 new NpgsqlParameter("@lx",NpgsqlDbType.Char,40){
      Value ="ty1"},
                  new NpgsqlParameter("@jbxx_jbh",NpgsqlDbType.Double,40){
      Value =1}

            };
            int a = pghelper.ExecuteNonQuery("update jbxx set modifiedtime=@modifiedtime,jbxx_lx=@lx where jbxx_jbh=@jbxx_jbh", pms);

            Console.WriteLine(a);

            //int a = pghelper.ExecuteSQL("update jbxx set modifiedtime='" + System.DateTime.Now.ToString() + "'");
            //Console.WriteLine(a);

            Console.Read();
        }

helper类转载于 https://www.cnblogs.com/luokunlun/p/luokunlun.html