無法在BaseX

Question

使用XQuery執行乘法考慮一個XML文件定義爲：

<?xml version="1.0"?> 
<sports> 
    <teams> 
    <team tno="t100"> 
      <tname>Knights</tname> 
      <city>London</city> 
     </team> 
     <team tno="t200"> 
      <tname>Dukes</tname> 
      <city>Surrey</city> 
     </team> 
     <team tno="t300"> 
      <tname>Kings</tname> 
      <city>Leeds</city> 
     </team>  
    </teams> 

    <players> 
    <player pid="p501"> 
      <pname>Simon</pname> 
      <city>London</city> 
     </player> 
     <player pid="p502"> 
      <pname>Andrew</pname> 
      <city>Birmingham</city> 
     </player> 
     <player pid="p503"> 
      <pname>Mike</pname> 
      <city>London</city> 
     </player>  
    </players> 


    <parts> 
     <part pno="801">    
      <pname>Right Gloves</pname> 
      <price>8.99</price> 
     </part> 
     <part pno="901">    
      <pname>Left Gloves</pname> 
      <price>9.99</price> 
     </part> 
     <part pno="851">    
      <pname>Left Pad</pname> 
      <price>33.00</price> 
     </part> 
     <part pno="951">    
      <pname>Right Pad</pname> 
      <price>43.00</price> 
     </part> 
    </parts> 

    <orders>  
     <order ono="61" playerNum="p501" team="t200" > 
      <kits> 
       <kit> 
        <pNum>801</pNum> 
        <qty>11</qty> 
       </kit> 
      </kits> 
     </order> 
     <order ono="62" playerNum="p501" team="t100" > 
      <kits> 
       <kit> 
        <pNum>901</pNum> 
        <qty>12</qty> 
       </kit> 

      </kits> 
     </order> 

     <order ono="63" playerNum="p502" team="t300" > 
      <kits> 
       <kit> 
        <pNum>851</pNum> 
        <qty>9</qty> 
       </kit> 

      </kits> 
     </order> 

     <order ono="64" playerNum="p503" team="t300" > 
      <kits> 
       <kit> 
        <pNum>951</pNum> 
        <qty>16</qty> 
       </kit> 

      </kits> 
     </order> 


     <order ono="65" playerNum="p503" team="t200" > 
      <kits> 
       <kit> 
        <pNum>801</pNum> 
        <qty>12</qty> 
       </kit> 
       <kit> 
        <pNum>901</pNum> 
        <qty>16</qty> 
       </kit> 
       <kit> 
        <pNum>851</pNum> 
        <qty>13</qty> 
       </kit> 
      </kits> 
     </order> 

    </orders> 
</sports> 

，我嘗試運行是獲得總定價一定的順序查詢（說爲了65）。在BaseX查詢是：

let $d:=doc("sports.xml") 
let $o:=$d/sports/orders/order[@ono=65] 
let $p:=$d/sports/parts/part 
for $k in $o/kits/kit 
return <OrderCost> 
({$k/qty})*({$p[@pno=$k/pNum]/price}) 
</OrderCost> 

我的輸出：

<OrderCost> 
(<qty>12</qty>)*(<price>8.99</price>) 
</OrderCost> 
<OrderCost> 
(<qty>16</qty>)*(<price>9.99</price>) 
</OrderCost> 
<OrderCost> 
(<qty>13</qty>)*(<price>33.00</price>) 
</OrderCost> 

我無法乘以相應的價格的數量，然後得到的總和。我在這裏做錯了什麼？

Answer 1

當創建元素時，評估大括號內的所有內容（並且沒有評估大括號之外的內容）。由於您只在變量上加上了大括號，只有這些變量被替換，但乘法不會被執行。

替換該行：

{ $k/qty * $p[@pno=$k/pNum]/price }