Question

我正在尝试使用SPARQL和Wikidata查询服务从字符串中识别出最长的三个子字符串，然后对其进行排名

字符串中按长度划分的子字符串
通过那些最长的子字符串中的任何一个的长度的字符串。

我设法从字符串中识别出第一个和第二个子字符串，当然可以创建类似的附加行来解决该问题，但这看起来很丑陋且效率低下，所以我想知道这里是否有人知道更好的获取方法在那里。

这是代码的简化版本，尽管我留下了一些辅助变量，因为我正在使用这些变量来跟踪途中的进度。您可以here尝试一下。

对this comment的响应的澄清：如果有必要将此查询视为子查询，并将其与另一个子查询的结果一起提供，这对我来说很好。要了解我要记住的用途，请参阅this demo。

SELECT * WHERE {
  {
    VALUES (?title) {
      ("What are the longest three words in this string?")
      ("A really complicated title")
      ("OneWordTitleInCamelCase")
      ("Thanks for your help!")
    }
  }
  BIND(STRLEN(REPLACE(?title, " ", "")) AS ?titlelength)

  BIND(STRBEFORE(?title, " ") AS ?substring1)
  BIND(STRLEN(REPLACE(?substring1, " ", "")) AS ?substring1length)
  BIND(STRAFTER(?title, " ") AS ?postfix)
  BIND(STRLEN(REPLACE(?postfix, " ", "")) AS ?postfixlength)
  BIND(STRBEFORE(?postfix, " ") AS ?substring2)
  BIND(STRLEN(REPLACE(?substring2, " ", "")) AS ?substring2length)
}
ORDER BY DESC(?substring1length)

预期结果：

longsubstring   substringlength
OneWordTitleInCamelCase 23
complicated 11
longest 7
really  6
string  6
Thanks  6
title   5
three   5
your    4
help    4

实际结果：

title   titlelength substring1  substring1length    postfix postfixlength   substring2  substring2length
Thanks for your help!   18  Thanks  6   for your help!  12  for 3
What are the longest three words in this string?    40  What    4   are the longest three words in this string? 36  are 3
A really complicated title  23  A   1   really complicated title    22  really  6
OneWordTitleInCamelCase 23      0       0       0

在Wikidata查询服务上使用SPARQL在字符串中找到三个最长的子字符串，并将它们在字符串中排名

0 个答案: