Question

我正尝试从以下示例XML中提取成人，儿童和婴儿的数量：

成人= AgeType 3
孩子= AgeType 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名成人
5个孩子
2名婴儿

下面的代码返回正确的结果，但是我想避免将cross apply输入到<Customer>标签中（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

有人能找到其他更有效率的逻辑吗？我当时在考虑像下面这样在count标签上使用sum或<Customer>，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。

对于其他年龄类型，请遵循相同的模式。

基于不同属性类型的XML值总和

1 个答案: