Oracle wm_concat（）函数的实际运用

作用：把一个数据表中多条记录的指定数据列值，以逗号（,）间隔形式返回。

select decode(V_VALUE_TYPE,'01',wm_concat(order_code),
                                                        '02',wm_concat(to_char(order_date,'yyyy-mm-dd')),
                                                        '03',wm_concat(trim(remark))
                                          )
                                          into ls_return_string              
                            from (
                                   select order_code,factory_code,order_type,order_date,trunc(order_date,'month') order_date_month,remark
                                   from sts_env_report_infor
                                   where  FACTORY_CODE = V_FACTORY_CODE
                                          and
                                          ORDER_TYPE   = V_FLAG
                                          and
                                          trunc(ORDER_DATE,'month')= decode(ln_row,1,V_REPORT_DATE,ldt_max_date)                           
                                 )
                            group by factory_code,order_type,order_date_month;