как обернуть результаты xquery в элементы? - PullRequest
0 голосов
/ 07 октября 2019

Как обернуть каждый результат в элемент <book_result>?

сам xquery:

<new_cat>{
for $x in catalog/book
order by $x/title
return ($x/title, $x/author)
}</new_cat>

, который работает нормально, но заголовок и автор не переносятсяв новой книге:

thufir@dur:~/basex/microsoft$ 
thufir@dur:~/basex/microsoft$ basex -i w3school_data title_author.xq
<new_cat>
  <title>Creepy Crawlies</title>
  <author>Knorr, Stefan</author>
  <title>Lover Birds</title>
  <author>Randall, Cynthia</author>
  <title>MSXML3: A Comprehensive Guide</title>
  <author>O'Brien, Tim</author>
  <title>Maeve Ascendant</title>
  <author>Corets, Eva</author>
  <title>Microsoft .NET: The Programming Bible</title>
  <author>O'Brien, Tim</author>
  <title>Midnight Rain</title>
  <author>Ralls, Kim</author>
  <title>Oberon's Legacy</title>
  <author>Corets, Eva</author>
  <title>Paradox Lost</title>
  <author>Kress, Peter</author>
  <title>Splish Splash</title>
  <author>Thurman, Paula</author>
  <title>The Sundered Grail</title>
  <author>Corets, Eva</author>
  <title>Visual Studio 7: A Comprehensive Guide</title>
  <author>Galos, Mike</author>
  <title>XML Developer's Guide</title>
  <author>Gambardella, Matthew</author>
</new_cat>thufir@dur:~/basex/microsoft$ 
thufir@dur:~/basex/microsoft$ 

база данных:

thufir@dur:~/basex/microsoft$ 
thufir@dur:~/basex/microsoft$ basex -i w3school_data /
<catalog>
  <book id="bk101">
    <author>Gambardella, Matthew</author>
    <title>XML Developer's Guide</title>
    <genre>Computer</genre>
    <price>44.95</price>
    <publish_date>2000-10-01</publish_date>
    <description>An in-depth look at creating applications 
      with XML.</description>
  </book>
  <book id="bk102">
    <author>Ralls, Kim</author>
    <title>Midnight Rain</title>
    <genre>Fantasy</genre>
    <price>5.95</price>
    <publish_date>2000-12-16</publish_date>
    <description>A former architect battles corporate zombies, 
      an evil sorceress, and her own childhood to become queen 
      of the world.</description>
  </book>
  <book id="bk103">
    <author>Corets, Eva</author>
    <title>Maeve Ascendant</title>
    <genre>Fantasy</genre>
    <price>5.95</price>
    <publish_date>2000-11-17</publish_date>
    <description>After the collapse of a nanotechnology 
      society in England, the young survivors lay the 
      foundation for a new society.</description>
  </book>
  <book id="bk104">
    <author>Corets, Eva</author>
    <title>Oberon's Legacy</title>
    <genre>Fantasy</genre>
    <price>5.95</price>
    <publish_date>2001-03-10</publish_date>
    <description>In post-apocalypse England, the mysterious 
      agent known only as Oberon helps to create a new life 
      for the inhabitants of London. Sequel to Maeve 
      Ascendant.</description>
  </book>
  <book id="bk105">
    <author>Corets, Eva</author>
    <title>The Sundered Grail</title>
    <genre>Fantasy</genre>
    <price>5.95</price>
    <publish_date>2001-09-10</publish_date>
    <description>The two daughters of Maeve, half-sisters, 
      battle one another for control of England. Sequel to 
      Oberon's Legacy.</description>
  </book>
  <book id="bk106">
    <author>Randall, Cynthia</author>
    <title>Lover Birds</title>
    <genre>Romance</genre>
    <price>4.95</price>
    <publish_date>2000-09-02</publish_date>
    <description>When Carla meets Paul at an ornithology 
      conference, tempers fly as feathers get ruffled.</description>
  </book>
  <book id="bk107">
    <author>Thurman, Paula</author>
    <title>Splish Splash</title>
    <genre>Romance</genre>
    <price>4.95</price>
    <publish_date>2000-11-02</publish_date>
    <description>A deep sea diver finds true love twenty 
      thousand leagues beneath the sea.</description>
  </book>
  <book id="bk108">
    <author>Knorr, Stefan</author>
    <title>Creepy Crawlies</title>
    <genre>Horror</genre>
    <price>4.95</price>
    <publish_date>2000-12-06</publish_date>
    <description>An anthology of horror stories about roaches,
      centipedes, scorpions  and other insects.</description>
  </book>
  <book id="bk109">
    <author>Kress, Peter</author>
    <title>Paradox Lost</title>
    <genre>Science Fiction</genre>
    <price>6.95</price>
    <publish_date>2000-11-02</publish_date>
    <description>After an inadvertant trip through a Heisenberg
      Uncertainty Device, James Salway discovers the problems 
      of being quantum.</description>
  </book>
  <book id="bk110">
    <author>O'Brien, Tim</author>
    <title>Microsoft .NET: The Programming Bible</title>
    <genre>Computer</genre>
    <price>36.95</price>
    <publish_date>2000-12-09</publish_date>
    <description>Microsoft's .NET initiative is explored in 
      detail in this deep programmer's reference.</description>
  </book>
  <book id="bk111">
    <author>O'Brien, Tim</author>
    <title>MSXML3: A Comprehensive Guide</title>
    <genre>Computer</genre>
    <price>36.95</price>
    <publish_date>2000-12-01</publish_date>
    <description>The Microsoft MSXML3 parser is covered in 
      detail, with attention to XML DOM interfaces, XSLT processing, 
      SAX and more.</description>
  </book>
  <book id="bk112">
    <author>Galos, Mike</author>
    <title>Visual Studio 7: A Comprehensive Guide</title>
    <genre>Computer</genre>
    <price>49.95</price>
    <publish_date>2001-04-16</publish_date>
    <description>Microsoft Visual Studio 7 is explored in depth,
      looking at how Visual Basic, Visual C++, C#, and ASP+ are 
      integrated into a comprehensive development 
      environment.</description>
  </book>
</catalog>thufir@dur:~/basex/microsoft$ 
thufir@dur:~/basex/microsoft$ 

Но просто хочу, чтобы каждый результат был отдельной книгой. Я попытался просто обернуть return как:

thufir@dur:~/basex/microsoft$ 
thufir@dur:~/basex/microsoft$ basex -i get_books.xq 
BaseX 9.0.1 [Standalone]
Try 'help' to get more information.
> 
> exit
See you.
thufir@dur:~/basex/microsoft$ 
thufir@dur:~/basex/microsoft$ cat get_books.xq 
<new_cat>{
for $x in catalog/book
order by $x/title
return <new_book>($x/title, $x/author)</new_book>
}</new_cat>
thufir@dur:~/basex/microsoft$ 

, но, очевидно, это не работает.

см. Также:

https://stackoverflow.com/a/58265691/262852

1 Ответ

1 голос
/ 07 октября 2019

Попытка return <new_book>($x/title, $x/author)</new_book> подходит для создания всех этих new_book элементов, но для их заполнения необходимо использовать фигурные скобки: return <new_book>{$x/title, $x/author}</new_book> (см. https://www.w3.org/TR/xquery-31/#dt-enclosed-expression и https://www.w3.org/TR/xquery-31/#id-element-constructor).

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