在PB中如何實現(xiàn)數(shù)據(jù)模糊查詢（五）

9.5 DataWindow: dw_where的 ue_where 事件
     功能：形成WHERE子句,并更新語法框。
     string hzcol, ywcol, sValue, sType //, sWhere
     //sWhere 現(xiàn)為實例變量,在wroot_query中為局部變量.
     string sOper, sLog, sLeft_kh,sRight_kh, tmpsValue
     long left_kh,right_kh //左、右括號數(shù)
     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行以前所有中間為空或
     //者輸入不完整的行, 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
     //檢查左右括號是否匹配, 即其數(shù)量是否一樣多.
     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 = "查詢條件中左括號比右括號多了" + String(i) + "個"
     else
     sValue = "查詢條件中左括號比右括號少了" + String(-i) + "個"
     end if
     if MessageBox("綜合查詢輸入錯誤",sValue + ",請改正；" + &
     "~r~n~r~n否則，所有查詢條件將被忽略。",None!,OKCancel!,2)=1 then
     return 1
     else
     dw_where.setfocus()
     return 0
     end if
     end if
     //形成WHERE子句,并更新語法框。
     sWhere = ""
     For i = 1 to MaxEditRow
     hzcol = GetItemString(i,"column1")
     sOper = space(1) + GetItemString(i,"operator") + space(1)
     // 去掉空格鍵
     sValue = Trim(GetItemString(i,"value"))
     sLeft_kh = GetItemString(i,"precol") //保存左括號
     if isNull(sLeft_kh) then sLeft_kh = ""
     if Pos(sValue,")",1) > 0 then //保存右括號
     sRight_kh = Right(sValue,(Len(sValue) - Pos(sValue,")",1) + 1))
     else
     sRight_kh = ""
     end if
     sValue = inv_string.of_globalreplace(sValue,"'","") //去掉sValue中的單引號.
     sValue = inv_string.of_globalreplace(sValue,'"','') //去掉sValue中的雙引號.
     sValue = inv_string.of_globalreplace(sValue,")","") //去掉sValue中的右括號.
     sLog = GetItemString(i,"logical")
     if sLog = "" or isNull(sLog) then
     sLog = "and"
     dw_where.SetItem(i,"logical","and")
     end if