Text 如何计算XML中的元素数？

我希望在数据库中获得有关数据库的基本元数据。具体地说，由根

文本
元素包围的
行
元素的数量

类似于我期望
COUNT
在
SQL
中返回的值——一个整数

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$ 

代码：

我想您只是想使用
count（/text/line）
 从Martin的回答中，我发现从basex本身来看很容易：

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$ 

谢谢，我想这将在Java上运行，但我希望也能在FLWOR上运行。我认为是线路上的迭代导致FLWOR崩溃？我添加了一个“答案”来详细说明。我不认为有任何理由使用flower，但如果是这样，您显然希望
count（for…return…
）。XQuery初学者犯的最大错误之一（尤其是那些来自SQL的人）是将FLWOR表达式作为每个问题的解决方案。对于绝大多数查询，FLWOR表达式都是多余的。
xquery version "3.0";

for $line in db:open("people")
for $index at $count in $line/text/line
return $count

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$ 

xquery version "3.0";

count(
for $line in db:open("people")
return $line/text/line)