public static void GetTables(Members src)
    {

        OracleConnection conn1 = MyConnectionClass.GetConnection(src.DB, src.ID, src.Password);

        conn1.Open();
        using (OracleCommand command= new OracleCommand("SELECT * FORM DBA_USERS WHERE USER NAME=" + src.ID + " and PASSWORD=" + src.Password + "", conn1))
        {
            using (OracleDataReader reader = command.ExecuteReader())
            {
                int count = 0;
                while (reader.Read())
                {
                    count = count + 1;
                }
            }
        }
  }

SELECT * FROM DBA_USERS WHERE USERNAME=" + src.ID + " and PASSWORD=" + src.Password + ""

SELECT * FROM DBA_USERS WHERE USERNAME=:uname and PASSWORD=:pwd