无法使用python SPARQLWrapper从GraphDB中删除任何三元组

问题描述

我正在尝试使用python的SPARQLWrapper和我在此处找到的代码段从GraphDB中删除一个简单的三元组（版本= GraphDB free）：https://github.com/RDFLib/sparqlwrapper-更新示例。我总是得到以下异常： SPARQLWrapper.SPARQLExceptions.QueryBadFormed：QueryBadFormed：错误的请求已发送到端点，可能是sparql查询的格式错误。

我的代码是：

    sparql = SPARQLWrapper('http://192.168.0.242:7200/repositories/DataCitation')
    sparql.setMethod(POST)

    sparql.setQuery("""
    PREFIX pub: <http://ontology.ontotext.com/taxonomy/>

    delete where {
        <http://ontology.ontotext.com/resource/tsk9hdnas934> pub:occupation "Cook".
    }
    """)

    results = sparql.query()
    print(results.response.read())

当我向相同的端点执行“询问”或“选择”语句时，我得到一个有效的结果。仅更新语句不起作用。

这是完整的堆栈跟踪

/home/filip/anaconda3/envs/TripleStoreCitationFramework/bin/python /home/filip/PycharmProjects/TripleStoreCitationFramework/GraphDB/Playground.py
Traceback (most recent call last):
  File "/home/filip/anaconda3/envs/TripleStoreCitationFramework/lib/python3.8/site-packages/SPARQLWrapper/Wrapper.py",line 1073,in _query
    response = urlopener(request)
  File "/home/filip/anaconda3/envs/TripleStoreCitationFramework/lib/python3.8/urllib/request.py",line 222,in urlopen
    return opener.open(url,data,timeout)
  File "/home/filip/anaconda3/envs/TripleStoreCitationFramework/lib/python3.8/urllib/request.py",line 531,in open
    response = meth(req,response)
  File "/home/filip/anaconda3/envs/TripleStoreCitationFramework/lib/python3.8/urllib/request.py",line 640,in http_response
    response = self.parent.error(
  File "/home/filip/anaconda3/envs/TripleStoreCitationFramework/lib/python3.8/urllib/request.py",line 569,in error
    return self._call_chain(*args)
  File "/home/filip/anaconda3/envs/TripleStoreCitationFramework/lib/python3.8/urllib/request.py",line 502,in _call_chain
    result = func(*args)
  File "/home/filip/anaconda3/envs/TripleStoreCitationFramework/lib/python3.8/urllib/request.py",line 649,in http_error_default
    raise HTTPError(req.full_url,code,msg,hdrs,fp)
urllib.error.HTTPError: HTTP Error 400: 

During handling of the above exception,another exception occurred:

Traceback (most recent call last):
  File "/home/filip/PycharmProjects/TripleStoreCitationFramework/GraphDB/Playground.py",line 6,in <module>
    citing.delete_triples("s")
  File "/home/filip/PycharmProjects/TripleStoreCitationFramework/GraphDB/DataCiting.py",line 32,in delete_triples
    results = sparql.query()
  File "/home/filip/anaconda3/envs/TripleStoreCitationFramework/lib/python3.8/site-packages/SPARQLWrapper/Wrapper.py",line 1107,in query
    return QueryResult(self._query())
  File "/home/filip/anaconda3/envs/TripleStoreCitationFramework/lib/python3.8/site-packages/SPARQLWrapper/Wrapper.py",line 1077,in _query
    raise QueryBadFormed(e.read())
SPARQLWrapper.SPARQLExceptions.QueryBadFormed: QueryBadFormed: a bad request has been sent to the endpoint,probably the sparql query is bad formed. 

响应： b'缺少参数：查询'

解决方法

您需要插入语句的端点不是用于普通查询的简单SPARQL端点，而是专用的/ statements端点：

http：/// repositories // statements

此端点还用于DELETE语句。

您可以在RDF4J文档中查找一些示例。 此外，如果要通过查询字符串传递数据，而不是将其作为请求正文的一部分，则需要意识到以下事实：该数据必须以“？update =“开头，而不是“？query =”开头。