有两种方法可以通过API或CMD将数据加载到tdb中。多得益于@ASKW并经由API @AndyS
1装入数据
这些代码需要被执行一次尤其是readModel
线这将花费很长的时间。
String directory = "tdb";
Dataset dataset = TDBFactory.createDataset(directory);
dataset.begin(ReadWrite.WRITE);
Model tdb = dataset.getDefaultModel();
String source = "yagoMetaFacts.ttl";
FileManager.get().readModel(tdb, source);
dataset.commit(); //Important!! This is to commit the data to tdb.
dataset.end();
的数据加载到TDB后,我们可以用以下代码来查询。而且不需要再次加载数据。通过CMD
String directory = "path\\to\\tdb";
Dataset dataset = TDBFactory.createDataset(directory);
Model tdb = dataset.getDefaultModel();
String queryString = "SELECT DISTINCT ?p WHERE { ?s ?p ?o. }";
Query query = QueryFactory.create(queryString);
try(QueryExecution qexec = QueryExecutionFactory.create(query, tdb)){
ResultSet results = qexec.execSelect();
ResultSetFormatter.out(System.out, results, query) ;
}
2加载数据
加载数据
>tdbloader --loc=path\to\tdb path\to\dataset.ttl
要查询
>tdbquery --loc=path\to\tdb --query=q1.rq
q1.rq是存储查询文件 应该得到的结果像这样
-------------------------------------------------------
| p |
=======================================================
| <http://yago-knowledge.org/resource/hasGloss> |
| <http://yago-knowledge.org/resource/occursSince> |
| <http://yago-knowledge.org/resource/occursUntil> |
| <http://yago-knowledge.org/resource/byTransport> |
| <http://yago-knowledge.org/resource/hasPredecessor> |
| <http://yago-knowledge.org/resource/hasSuccessor> |
| <http://www.w3.org/2000/01/rdf-schema#comment> |
-------------------------------------------------------
当然,如果你调用'readModel'的话。你为什么不尝试没有这条线? – AKSW
嗨,我尝试运行没有readModel线,但我没有得到结果。如果我不指出我需要的数据集,tdb如何知道要使用哪个数据集? – Charlotte
我想你必须调用'tdb.commit',参见https://jena.apache.org/documentation/tdb/tdb_transactions.html#write-transactions – AKSW