在PB中如何实现数据模糊查询（五）

  功能：形成WHERE子句,并更新语法框。

  string hzcol, ywcol, sValue, sType //, sWhere
  //sWhere 现为实例变量,在wroot_query中为局部变量.
  string sOper, sLog, sLeft_kh,sRight_kh, tmpsValue
  long left_kh,right_kh //左、右括号数
  integer i, rownum, delnum //, typenum
  dwItemStatus l_status
  if ib_changed = true then
  ib_changed = false
  else
  return 0
  end if
  rownum = dw_where.RowCount()
  //去掉dw_where中MaxEditRow行以前所有中间为空或
  //者输入不完整的行, 并更新MaxEditRow.
  i = 1
  delnum = 0
  DO WHILE i <= MaxEditRow
  l_status = dw_where.GetItemStatus(i,0, Primary!)
  if l_status <> New! then
  hzcol = GetItemString(i,"column1")
  sValue = GetItemString(i,"value")
  if (hzcol = "" or isnull(hzcol)) or (sValue = "" or isnull(sValue)) then
  dw_where.DeleteRow(i)
  delnum += 1
  MaxEditRow += -1
  Continue
  end if
  else
  dw_where.DeleteRow(i)
  delnum += 1
  MaxEditRow += -1
  Continue
  end if
  i += 1
  LOOP
  For i = 1 to DelNum
  dw_where.InsertRow(0)
  Next
  //检查左右括号是否匹配, 即其数量是否一样多.
  For i = 1 to MaxEditRow
  l_status = dw_where.GetItemStatus(i,0, Primary!)
  if l_status <> New! then
  left_kh += inv_string.of_countoccurrences(GetItemString(i,"precol"),"(")
  right_kh += inv_string.of_countoccurrences(GetItemString(i,"value"),")")
  end if
  Next
  i = left_kh - right_kh
  if i <> 0 then
  if i > 0 then
  sValue = "查询条件中左括号比右括号多了" + String(i) + "个"
  else
  sValue = "查询条件中左括号比右括号少了" + String(-i) + "个"
  end if
  if MessageBox("综合查询输入错误",sValue + ",请改正；" + &
  "~r~n~r~n否则，所有查询条件将被忽略。",None!,OKCancel!,2)=1 then
  return 1
  else
  dw_where.setfocus()
  return 0
  end if
  end if
  //形成WHERE子句,并更新语法框。
  sWhere = ""
  For i = 1 to MaxEditRow
  hzcol = GetItemString(i,"column1")
  sOper = space(1) + GetItemString(i,"operator") + space(1)
  // 去掉空格键
  sValue = Trim(GetItemString(i,"value"))
  sLeft_kh = GetItemString(i,"precol") //保存左括号
  if isNull(sLeft_kh) then sLeft_kh = ""
  if Pos(sValue,")",1) > 0 then //保存右括号
  sRight_kh = Right(sValue,(Len(sValue) - Pos(sValue,")",1) + 1))
  else
  sRight_kh = ""
  end if
  sValue = inv_string.of_globalreplace(sValue,"‘","") //去掉sValue中的单引号.
  sValue = inv_string.of_globalreplace(sValue,‘"‘,‘‘) //去掉sValue中的双引号.
  sValue = inv_string.of_globalreplace(sValue,")","") //去掉sValue中的右括号.
  sLog = GetItemString(i,"logical")
  if sLog = "" or isNull(sLog) then
  sLog = "and"
  dw_where.SetItem(i,"logical","and")
  end if