Question

<authors> {
for $a in fn:distinct-values(doc("data.xml")/books/book/author/text())
 return  <name> {$a} </name> 
 {
    for $b in doc("data.xml")/books/book[author/text() = $a]
    return <book> {$b/title/text()}</book>
 }
}
</authors>

这是我的代码，当我运行此代码时，出现语法错误：

4,1: static error [err:XPST0003]: invalid expression: syntax error, unexpected expression (missing comma "," between expressions?)

此代码有什么问题？

Answer 1

从你的查询来看，你想要输出的输出格式并不完全清楚，但是我能想出的最接近语法正确的是（请注意，大括号仅用于输出xml中的内容）语法）：

<authors> {
for $a in fn:distinct-values(doc("data.xml")/books/book/author/text())
 return  (<name> {$a} </name>,
    for $b in doc("data.xml")/books/book[author/text() = $a]
    return <book> {$b/title/text()}</book>)
}
</authors>

要回归的更“逻辑”的结构是这样的：

<authors> {
for $a in fn:distinct-values(doc("data.xml")/books/book/author/text())
 return  <author>
           <name> {$a} </name>
           { for $b in doc("data.xml")/books/book[author/text() = $a]
               return <book> {$b/title/text()}</book>
           }
         </author>
}
</authors>

Xquery语法错误

1 个答案: