StringBuilder strSql = new StringBuilder();
           strSql.Append("select * from topic ");
           strSql.Append("where topicid=@tid");           SqlParameter[] parameters = {
                    new SqlParameter("@tid",SqlDbType.Int,4),
                                       };
           parameters[0].Value = 18;
为什么老是报错:必须声明标量变量 "@tid"。谢谢