Question

我有两个用于代表市场的XML文件，第一个文件是包含账单信息类型（销售，购买）的账单，这是文件：

<?xml version="1.0" encoding="utf-8"?>
<root>
 <bill>
     <billid>1</billid>
     <billtype>sales</billtype>
     <billdate>10/10/2013</billdate>
 </bill>
  <bill>
     <billid>2</billid>
     <billtype>Purchase</billtype>
     <billdate>15/10/2013</billdate>
 </bill>
  <bill>
     <billid>3</billid>
     <billtype>Purchase</billtype>
     <billdate>20/10/2013</billdate>
 </bill>
  <bill>
     <billid>4</billid>
     <billtype>sales</billtype>
     <billdate>16/10/2013</billdate>
 </bill>
</root>

，第二个文件包含该账单中的产品信息，如下所示：

<?xml version="1.0" encoding="utf-8"?>
<root>
  <itembill>
   <itembill_id>1</itembill_id>
   <itemid_ref>2</itemid_ref>
   <billid_ref>2</billid_ref>
   <price>20000</price> 
  </itembill>
   <itembill>
   <itembill_id>2</itembill_id>
   <itemid_ref>3</itemid_ref>
   <billid_ref>3</billid_ref>
   <price>250000</price> 
  </itembill>
  <itembill>
   <itembill_id>4</itembill_id>
   <itemid_ref>1</itemid_ref>
   <billid_ref>2</billid_ref>
   <price>140000</price> 
  </itembill>
  <itembill>
   <itembill_id>5</itembill_id>
   <itemid_ref>2</itemid_ref>
   <billid_ref>1</billid_ref>
   <price>10000</price> 
  </itembill>
</root>

其中billid_ref是外键（billid），

问题是：我希望 X查询为分组分组执行 SUM 帐单类型
我怎样才能做到这一点？！

我试过这个：

<catalog>
   { 
     for $x in doc('bills')//bill,
     $y in doc('itembills')//itembill where $y/billid_ref = $x/billid and $x/billtype = "Purchase"

     return
        <item >
           {
sum ($y/price/text())
           }

        </item>

   }
<catalog>

但效果不佳的结果是：

<catalog>
  <item>20000</item>
  <item>140000</item>
  <item>250000</item>
  <item>30000</item>
<catalog>

Answer 1

xquery 3.0中有一个分组运算符，但xquery 1.0中没有。在1.0中，您可以创建一系列值并将它们相加：

<catalog>{
for $x in doc('bills')//bill
  let $y := doc('itembills')//itembill where $y/billid_ref = $x/billid and $x/billtype = "Purchase"  
 return
    <item >
       { sum ($y/price/text()) }
    </item>
}</catalog>

但是如果没有其他循环（对于billtype in ...）

，您将无法按billtype分组

在XQUERY中汇总和分组

1 个答案: