通过SPARQL从DBpedia中提取化学数据 [英] Extract Chemical Data from DBpedia via SPARQL
问题描述
我想知道如何向DDBpedia提交SPARQL查询,并返回一个表,该表包含在Wikipedia化学箱信息框模板中找到的信息,例如分子量或分子式。
因此,第一步只是要进行查询,其结果应为包含分子式和分子重量属性的化学物质的列表。但是以下内容没有返回结果:
SELECT *在哪里{
?y rdf:type dbpedia-owl:ChemicalSubstance。
?y rdfs:label?Name。
?y dbpedia:molecularWeight?molecularWeight。
?y dbpedia:formula?formula。
可选{?y dbpedia-owl:iupacName?iupacname}。
FILTER(langMatches(lang(?Name), en))
}
限制50
所以我陷入了困境。此查询出问题了吗,还是DBPedia确实没有从Wikipedia的化学盒中收集该信息?
dbpedia:molecularWeight
和 dbpedia:formula
。正确的命名空间应为 dbpedia2
。
此外,似乎很少有条目具有 dbpedia-owl:iupacName
, dbpedia2:molecularWeight
和 dbpedia2:formula
。
选择*位置{
?y rdf:type dbpedia-owl:ChemicalSubstance。
?y rdfs:label?Name。
可选{?y dbpedia2:formula?formula}。
可选{?y dbpedia2:molecularWeight?molecularWeight}。
可选{?y dbpedia-owl:iupacName?iupacname}。
FILTER(langMatches(lang(?Name), en))
}
限制50
<$ p $获取类型 dbpedia-owl:ChemicalSubstance
的所有已使用属性的列表p> 在不同位置选择SELECT {
?y rdf:type dbpedia-owl:ChemicalSubstance。
?y?rel?x
}
I'd like to know how to submit a SPARQL query to DDBpedia and be given back a table that includes the information found in the Wikipedia "chembox" info box template, such as molecular weight or formula.
So, the first step was just to make a query whose results should be a list of chemical substances that had the formula and molecularWeight properties included. But the following returns no results:
SELECT * WHERE {
?y rdf:type dbpedia-owl:ChemicalSubstance.
?y rdfs:label ?Name .
?y dbpedia:molecularWeight ?molecularWeight .
?y dbpedia:formula ?formula .
OPTIONAL {?y dbpedia-owl:iupacName ?iupacname} .
FILTER (langMatches(lang(?Name),"en"))
}
LIMIT 50
SPARQL Explorer at dbpedia.org
And so I'm stuck. Is something wrong with this query or does DBPedia really not collect that information from the Wikipedia chemboxes?
You caught the wrong namespace for both dbpedia:molecularWeight
and dbpedia:formula
. The correct namespace here would be dbpedia2
.
Furthermore, there seem rarely any entries having a dbpedia-owl:iupacName
, dbpedia2:molecularWeight
and dbpedia2:formula
.
SELECT * WHERE {
?y rdf:type dbpedia-owl:ChemicalSubstance.
?y rdfs:label ?Name .
OPTIONAL {?y dbpedia2:formula ?formula }.
OPTIONAL {?y dbpedia2:molecularWeight ?molecularWeight}.
OPTIONAL {?y dbpedia-owl:iupacName ?iupacname} .
FILTER (langMatches(lang(?Name),"en"))
}
LIMIT 50
To get the correct namespaces, you could either look at one example like this or get a list of all used properties for type dbpedia-owl:ChemicalSubstance
using
SELECT DISTINCT ?rel WHERE {
?y rdf:type dbpedia-owl:ChemicalSubstance.
?y ?rel ?x
}
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