维护同事编写的程序时遇到的一个问题，求达人解释一下
现在有三个表：
inv.yw_inv_m 入库单主表，inv.yw_inv_d 入库单子表，mdm.dm_material基础数据的物料表。

前台页面数的查询条件是：itemName也就是物料名称。执行的sql语句如下：
select
  inv_m.io_type_ as ioType,
  inv_m.make_date_ as makeDate,
  inv_m.make_psnname_ as makePsnName,
  inv_m.bill_status_ as billStatus,
  inv_m.audit_psnid_ as auditPsnId,
  inv_m.audit_psnname_ as auditPsnName,
    inv_m.inv_code_ as invCode,
    inv_d.qa_level_ as qaLevel,
    inv_d.asme_level_ as asmeLevel,
    inv_d.nuclear_level_ as nuclearLevel,
  inv_d.tech_spec_ as techSpec,
    inv_d.item_id_ as itemId,
    inv_d.id_ as id,
  inv_d.source_bill_mid_ as sourceBillMid,
    inv_d.source_bill_bid_ as sourceBillBid,
    inv_d.source_bill_code_ as sourceBillCode,
  inv_d.mid_ as mid,
    inv_d.item_qty_ as itemQty,
    inv_d.ware_id_ as wareId,
    inv_d.ware_name_ as wareName,
    inv_d.bin_id_ as binId,
    inv_d.bin_name_ as binName,
  inv_d.loc_id_ as locId,
    inv_d.loc_name_ as locName,
    inv_d.item_batch_ as itemBatch,
    inv_d.item_qty_assist_ as itemQtyOther,
    inv_d.note_ as note,
    inv_d.sup_id_ as supId,
  inv_d.sup_name_ as supName,
    inv_d.f_col1_ as fcol1,
  inv_d.f_col2_ as fcol2,
    inv_d.arrive_date_ as arriveDate,
  inv_d.order_code_ as orderCode,
    inv_d.buy_psnid_ as buyPsnid,
  inv_d.buy_psnname_ as buyPsnname,
    material.item_code_ as itemCode,
    material.item_name_ as itemName,
    material.item_spec_ as itemSpec,
    material.item_model_ as itemModel,
    material.assist_unit_code_ as unitCode,
    material.assist_unit_name_ as unitName,
    material.unit_name_ as assistName,
    material.change_rate_ as assistRate,
    material.item_texture_ || ' ' || material.item_model_ as textureAndModel,
    material.item_spec_ ||' '||material.thickness_series_rank_ ||' '||material.nose_preparation_form_ as newSpec,

    inv_d.f_col1_ ||' '|| inv_d.tech_spec_ ||' '|| inv_d.nuclear_level_ ||' '|| inv_d.asme_level_ ||' '|| inv_d.qa_level_ ||' '|| material.material_description_  as itemDescription,
  
    material.item_standard_ as itemGb,
    material.item_texture_ as itemTexture,
    material.nose_preparation_form_ as nosePreparationForm,
    material.thickness_series_rank_ as thicknessSeriesRank,
    material.material_description_  as materialDescription


    from  inv.yw_inv_m inv_m,
          inv.yw_inv_d inv_d,
          mdm.dm_material material
    where    1=1
      and io_flag_='I'
      and   inv_m.id_ = inv_d.mid_
      and   inv_d.item_id_ = material.id_
      and   exists(select 1  from inv.yw_inv_d inv_d , mdm.dm_material material where inv_m.id_ = inv_d.mid_ and inv_d.item_id_ = material.id_  and ((material.item_name_) like ('%碳钢%') or
&n