根据不同的属性类型求和 XML 值

Question

我正在尝试从以下示例中提取成人、children 和婴儿的数量 XML:

成人 = 3 岁
Children = 年龄类型 2
婴儿 = AgeType 1

然后计数指定该年龄类型的数量。正确的结果是：

35 位成人
5 Children
2 个婴儿

下面的代码 returns 是正确的结果，但是我想避免 cross apply 进入 <Customer> 标签（因为每天有数亿）。

declare @a table(a xml)
insert into @a  
select '<Customers>
        <Customer AgeType="3" Count="10" />    
        <Customer AgeType="3" Count="20" />
        <Customer AgeType="3" Count="5" />       
        <Customer AgeType="2" Count="5" />
        <Customer AgeType="1" Count="2" />
        </Customers>'

select  
    sum(case when b.cust = 3 then b.cust*b.count_cust end)/3 as adt
    ,sum(case when b.cust = 2 then b.cust*b.count_cust end)/2 as chd
    ,sum(case when b.cust = 1 then b.cust*b.count_cust end)/1 as inf
from   (
select c.value('(@AgeType)','int') As cust
,c.value('(@Count)','int') As count_cust
from @a cross apply a.nodes('Customers/Customer') as t(c)
) as b

谁能找到其他更有效的逻辑？我正在考虑在 <Customer> 标签上使用 count 或 sum，如下所示，但是我无法获得正确的结果。

 a.value('count(Customers/Customer/@AgeType[.=3])','int') As adt
,a.value('count(Customers/Customer/@AgeType[.=2])','int') As chd
,a.value('count(Customers/Customer/@AgeType[.=1])','int') As inf

Answer 1

从

更改您的 XPath

count(Customers/Customer/@AgeType[.=3])

到

sum(Customers/Customer[@AgeType = 3]/@Count)

总结所有成人(@AgeType = 3) Customer @Count 属性值。

对其他年龄类型遵循相同的模式。

根据不同的属性类型求和 XML 值

Sum XML Value based on different attribute types

sql-server

xml

xpath

xquery

xquery-sql