如何统计XML中的元素个数？
提问于 2020-02-17 09:59:33
我希望在数据库中获得有关data的基本元数据。具体地说，就是被根text元素包围的line元素的数量。
类似于我期望COUNT在SQL中返回的内容--单个整数。
数据库：
thufir@dur:~/flwor/group$
thufir@dur:~/flwor/group$ basex
BaseX 9.0.1 [Standalone]
Try 'help' to get more information.
>
> open people
Database 'people' was opened in 225.24 ms.
>
> xquery /
<text>
<line>people</line>
<line>joe</line>
<line>phone1</line>
<line>phone2</line>
<line>phone3</line>
<line>sue</line>
<line>cell4</line>
<line>home5</line>
<line>alice</line>
<line>atrib6</line>
<line>x7</line>
<line>y9</line>
<line>z10</line>
</text>
Query executed in 215.13 ms.
>
> exit
See you.
thufir@dur:~/flwor/group$ 计算行数：
thufir@dur:~/flwor/group$
thufir@dur:~/flwor/group$ basex each.xq
1
2
3
4
5
6
7
8
9
10
11
12
13thufir@dur:~/flwor/group$ 代码：
xquery version "3.0";
for $line in db:open("people")
for $index at $count in $line/text/line
return $count
回答 2
Stack Overflow用户
回答已采纳
发布于 2020-02-17 11:16:56
我想您只是想使用count(/text/line)。
Stack Overflow用户
发布于 2020-02-17 11:23:47
从Martin的回答中，我看到从basex本身就很容易做到：
thufir@dur:~/flwor/group$
thufir@dur:~/flwor/group$ basex
BaseX 9.0.1 [Standalone]
Try 'help' to get more information.
>
> open people
Database 'people' was opened in 208.33 ms.
>
> xquery /
<text>
<line>people</line>
<line>joe</line>
<line>phone1</line>
<line>phone2</line>
<line>phone3</line>
<line>sue</line>
<line>cell4</line>
<line>home5</line>
<line>alice</line>
<line>atrib6</line>
<line>x7</line>
<line>y9</line>
<line>z10</line>
</text>
Query executed in 237.69 ms.
>
> xquery count(/text/line)
13
Query executed in 20.55 ms.
>
> exit
See you.
thufir@dur:~/flwor/group$ 但我也希望从一个xq文件中运行它：
xquery version "3.0";
count(
for $line in db:open("people")
return $line/text/line)页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/60259916
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