我正在尝试将此JSON文件映射到RDF,但我可能无法正确迭代以获取“值”的值,这些值位于度量数组中。
JSON:
{
"status": 0,
"body": {
"updatetime": 1528904042,
"timezone": "Europe\/Rome",
"measuregrps": [{
"grpid": 1154218424,
"attrib": 2,
"date": 1528902698,
"category": 1,
"brand": 1,
"modified": 1528902700,
"deviceid": null,
"measures": [{
"value": 7000,
"type": 11,
"unit": -2,
"algo": 0,
"fw": 0,
"fm": 131
}]
},
{
"grpid": 1154218987,
"attrib": 2,
"date": 1528902745,
"category": 1,
"brand": 1,
"modified": 1528902747,
"deviceid": null,
"measures": [{
"value": 7200,
"type": 11,
"unit": -2,
"algo": 0,
"fw": 0,
"fm": 131
}]
}
]
}
}
RML:
@prefix rr: <http://www.w3.org/ns/r2rml#>.
@prefix rml: <http://semweb.mmlab.be/ns/rml#> .
@prefix ql: <http://semweb.mmlab.be/ns/ql#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#>.
@prefix fo: <http://purl.org/ifo/#>.
###### Fitbit MAPPING #######
<#FitbitRestingHeartRate>
rml:logicalSource [
rml:source "provaJson.json";
rml:referenceFormulation ql:JSONPath;
rml:iterator "$.body.measuregrps";
];
rr:subjectMap [
rr:template "http://ifo.com/{grpid}";
rr:class fo:HeartRate;
];
rr:predicateObjectMap [
rr:predicate fo:hasTemporalRelationshipToPhysicalActivity;
rr:objectMap [
rr:constant fo:AtRest;
];
];
rr:predicateObjectMap [
rr:predicate fo:hasMeasure;
rr:objectMap [
rr:parentTriplesMap <#MeasureHeartRate>;
];
].
<#MeasureHeartRate>
rml:logicalSource [
rml:source "provaJson.json";
rml:referenceFormulation ql:JSONPath;
rml:iterator "$.body.measuregrps";
];
rr:subjectMap [
rr:template "http://ifo.com/{grpid}";
rr:class fo:Measure;
rml:iterator "$.body.measuregrps";
];
rr:predicateObjectMap [
rr:predicate fo:hasNumericalValue;
rr:objectMap [
rml:reference "@.measures.value";
rr:datatype xsd:float;
];
];
rr:predicateObjectMap [
rr:predicate fo:hasDescriptiveStatistic;
rr:objectMap [
rr:constant fo:average;
];
];
rr:predicateObjectMap [
rr:predicate fo:hasUnit;
rr:objectMap [
rr:constant fo:bpm;
];
].
感谢您的帮助, Chiara的
答案 0 :(得分:2)
适应JSON Path表达式使RML处理器能够检索心脏
费率值。
对于两个TriplesMap,我将它们更改为$.body.measuregrps.[*]
在每个measuregrps
条目上。
我为每个TriplesMap添加了a rr:TriplesMap
,以确保RML
处理器知道RDF描述了TriplesMap:
<#MeasureHeartRate>
a rr:TriplesMap;
rr:joinCondition
,它仅将心率值与
grpid
值相等时进行正确的测量:rr:predicateObjectMap [
rr:predicate fo:hasMeasure;
rr:objectMap [
rr:parentTriplesMap <#MeasureHeartRate>;
rr:joinCondition [
rr:child "grpid";
rr:parent "grpid";
];
];
].
<http://ifo.com/1154218987> <http://purl.org/ifo/#hasMeasure> <http://ifo.com/1154218987>
新的IRI格式还支持心脏以外的其他类型的测量 率。
映射规则:
@base <http://example.org> .
@prefix rr: <http://www.w3.org/ns/r2rml#> .
@prefix rml: <http://semweb.mmlab.be/ns/rml#> .
@prefix ql: <http://semweb.mmlab.be/ns/ql#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix fo: <http://purl.org/ifo/#> .
<#FitbitRestingHeartRate>
a rr:TriplesMap;
rml:logicalSource [
rml:source "provaJson.json";
rml:referenceFormulation ql:JSONPath;
rml:iterator "$.body.measuregrps.[*]";
];
rr:subjectMap [
rr:template "http://ifo.com/{grpid}";
rr:class fo:HeartRate;
];
rr:predicateObjectMap [
rr:predicate fo:hasTemporalRelationshipToPhysicalActivity;
rr:objectMap [
rr:constant fo:AtRest;
];
];
rr:predicateObjectMap [
rr:predicate fo:hasMeasure;
rr:objectMap [
rr:parentTriplesMap <#MeasureHeartRate>;
rr:joinCondition [
rr:child "grpid";
rr:parent "grpid";
];
];
].
<#MeasureHeartRate>
a rr:TriplesMap;
rml:logicalSource [
rml:source "provaJson.json";
rml:referenceFormulation ql:JSONPath;
rml:iterator "$.body.measuregrps.[*]";
];
rr:subjectMap [
rr:template "http://ifo.com/{grpid}/{date}/{measures.[*].type}";
rr:class fo:Measure;
];
rr:predicateObjectMap [
rr:predicate fo:hasNumericalValue;
rr:objectMap [
rml:reference "measures.[*].value";
rr:datatype xsd:float;
];
];
rr:predicateObjectMap [
rr:predicate fo:hasDescriptiveStatistic;
rr:objectMap [
rr:constant fo:average;
];
];
rr:predicateObjectMap [
rr:predicate fo:hasUnit;
rr:objectMap [
rr:constant fo:bpm;
];
].
输出:
<http://ifo.com/1154218424> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://purl.org/ifo/#HeartRate>.
<http://ifo.com/1154218424> <http://purl.org/ifo/#hasTemporalRelationshipToPhysicalActivity> <http://purl.org/ifo/#AtRest>.
<http://ifo.com/1154218424> <http://purl.org/ifo/#hasMeasure> <http://ifo.com/1154218424/1528902698/11>.
<http://ifo.com/1154218987> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://purl.org/ifo/#HeartRate>.
<http://ifo.com/1154218987> <http://purl.org/ifo/#hasTemporalRelationshipToPhysicalActivity> <http://purl.org/ifo/#AtRest>.
<http://ifo.com/1154218987> <http://purl.org/ifo/#hasMeasure> <http://ifo.com/1154218987/1528902745/11>.
<http://ifo.com/1154218424/1528902698/11> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://purl.org/ifo/#Measure>.
<http://ifo.com/1154218424/1528902698/11> <http://purl.org/ifo/#hasNumericalValue> "7000"^^<http://www.w3.org/2001/XMLSchema#float>.
<http://ifo.com/1154218424/1528902698/11> <http://purl.org/ifo/#hasDescriptiveStatistic> <http://purl.org/ifo/#average>.
<http://ifo.com/1154218424/1528902698/11> <http://purl.org/ifo/#hasUnit> <http://purl.org/ifo/#bpm>.
<http://ifo.com/1154218987/1528902745/11> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://purl.org/ifo/#Measure>.
<http://ifo.com/1154218987/1528902745/11> <http://purl.org/ifo/#hasNumericalValue> "7200"^^<http://www.w3.org/2001/XMLSchema#float>.
<http://ifo.com/1154218987/1528902745/11> <http://purl.org/ifo/#hasDescriptiveStatistic> <http://purl.org/ifo/#average>.
<http://ifo.com/1154218987/1528902745/11> <http://purl.org/ifo/#hasUnit> <http://purl.org/ifo/#bpm>.
注意:我为RML及其技术做出了贡献。