SPARQL HAVING 子句给出语法错误

Question

我正在尝试使用 this 和以下内容从 DBPedia 中获取超过 3 本书的作者：

SELECT ?author (COUNT(*) as ?count) WHERE {?works dbo:author ?author. }

Group by(?author)
ORDER BY DESC (?count)
HAVING (?count > 3)

但是我收到一个语法错误，当我删除我的 HAVING 子句时，其余部分工作正常，知道可能是什么问题吗？

Answer 1

你有： Group by(?author) ORDER BY DESC (?count) HAVING (?count > 3) 但是 HAVING 应该在 ORDER BY.

之前

Answer 2

错误告诉你“？count is used in the result set outside aggregate”所以基本上你应该使用 "aggregated solution" 你可以这样做：

SELECT ?author (COUNT(*) as ?count) WHERE {?works dbo:author ?author. }    
Group by ?author
HAVING (COUNT(*) > 3)
ORDER BY DESC (?count)

你可以看到here形式语法。

SPARQL HAVING clause giving syntax error