SPARQL Query Language for RDF
Contents
* 1. Intoduction
* 2. Making Simple Queries
* 3. RDF Term Constraints
* 4. SPARQL Syntax (语法)
o 4.1 IRIs (URIs)
o 4.2 平凡文字的语法 Syntax for Literals
o 4.3 查询变量的Syntax
o 4.4 空白节点的语法
o 4.5 三元组模型语法
o 4.6 谓-宾列表
o 4.7 宾语列表
o 4.8 复合列表
o 4.9 RDF集合
o 4.10 当rdf:type是谓词时可用a代替
* 5. Graph Patterns (模式)
o 5.1 Group Graph Patterns
o 5.2 Empty Group Pattern
o 5.3 Scope of Filters 过滤范围
* 6. Including Optional Values (可选值)
* 7. 匹配两个中的一个 Matching Alternatives
* 8. RDF Dataset 数据集合
* 9. 结果排序和修改 Solution Sequences and Modifiers
o 重复结果 Duplicate Soulution
* 10. 查询形式 Query Forms
* 11. 测试值 Testing Values
o 操作数数据类型Openrand Data Types
o 过滤评价 Filter Evaluation
* 12. SPARQL定义 Definition of SPARQL
o RDF Terms(术语)
1. Intoduction
* Turtle data format （Tutle数据格式）
2. Making Simple Queries
简单查询:
SELECT ?title
WHERE
{
<http://example.org/book/book1> <http://purl.org/dc/elements/1.1/title> ?title .
}
Building RDF Graphs, 用Construct代替Select:
CONSTRUCT { ?x foaf:name ?name }
WHERE { ?x org:employeeName ?name }
3. RDF Term Constraints
正则表达式过滤 FILTER regex():
PREFIX dc: <http://purl.org/dc/elements/1.1/>
SELECT ?title
WHERE { ?x dc:title ?title
FILTER regex(?title, "web", "i" )
}
4. SPARQL Syntax (语法)
4.1 IRIs (URIs)
同一个IRI的不同表示方式:
<http://example.org/book/book1>
BASE <http://example.org/book/>
<book1>
PREFIX book: <http://example.org/book/>
book:book1
4.2 平凡文字的语法 Syntax for Literals
4.3 查询变量的Syntax
'?','$' 两者是等价的
4.4 空白节点的语法
[ :p "v" ] .
[] :p "v" .
_:b57 :p "v" . //前面加_:的标签
[ :p "v" ] :q "w" . //空白节点的组合
简略空白节点:
[ foaf:name ?name ;
foaf:mbox <mailto:alice@example.org> ]
4.5 三元组模型语法
PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX : <http://example.org/book/>
SELECT $title
WHERE { :book1 dc:title $title }
4.6 谓-宾列表
?x foaf:name ?name ;
foaf:mbox ?mbox .
4.7 宾语列表
?x foaf:nick "Alice" , "Alice_" .
4.8 复合列表
?x foaf:name ?name ; foaf:nick "Alice" , "Alice_" .
等价于:
?x foaf:name ?name .
?x foaf:nick "Alice" .
?x foaf:nick "Alice_" .
4.9 RDF集合
(1 ?x 3 4) :p "w" .
4.10 当rdf:type是谓词时可用a代替
?x a :Class1 .
5. Graph Patterns (模式)
5.1 Group Graph Patterns
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT ?name ?mbox
WHERE {
?x foaf:name ?name .
?x foaf:mbox ?mbox .
}
5.2 Empty Group Pattern
{}
SELECT ?x WHERE {}
5.3 Scope of Filters 过滤范围
FILTER regex(?name, "Smith")
6. Including Optional Values (可选值)
Optional Pattern Matching
WHERE { ?x foaf:name ?name .
OPTIONAL { ?x foaf:mbox ?mbox }
}
Constraints in Optional Pattern Matching
SELECT ?title ?price
WHERE { ?x dc:title ?title .
OPTIONAL { ?x ns:price ?price . FILTER (?price < 30) }
}
Multiple Optional Graph Patterns
SELECT ?name ?mbox ?hpage
WHERE { ?x foaf:name ?name .
OPTIONAL { ?x foaf:mbox ?mbox } .
OPTIONAL { ?x foaf:homepage ?hpage }
}
7. 匹配两个中的一个 Matching Alternatives
UNION:
SELECT ?x ?y
WHERE { { ?book dc10:title ?x } UNION { ?book dc11:title ?y } }
8. RDF Dataset 数据集合
查询多个Graph中的信息
9. 结果排序和修改 Solution Sequences and Modifiers
排序 ORDER BY:
SELECT ?name
WHERE { ?x foaf:name ?name }
ORDER BY ?name
映射 Projection
重复结果 Duplicate Soulution
唯一 DISTINCT:
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT DISTINCT ?name WHERE { ?x foaf:name ?name }
简化 REDUCED:
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
SELECT REDUCED ?name WHERE { ?x foaf:name ?name }
偏移 OFFSET, 限制 LIMIT:
SELECT ?name
WHERE { ?x foaf:name ?name }
ORDER BY ?name
LIMIT 5
OFFSET 10
10. 查询形式 Query Forms
*
SELECT
Returns all, or a subset of, the variables bound in a query pattern match.
*
CONSTRUCT
Returns an RDF graph constructed by substituting variables in a set of triple templates.
*
ASK
Returns a boolean indicating whether a query pattern matches or not.
*
DESCRIBE
Returns an RDF graph that describes the resources found.
11. 测试值 Testing Values
操作数数据类型Openrand Data Types
* xsd:integer
* xsd:decimal
* xsd:float
* xsd:double
* xsd:string
* xsd:boolean
* xsd:dateTime
过滤评价 Filter Evaluation
A B A || B A && B
T T T T
T F T F
F T T F
F F F F
T E T E
E T T E
F E E F
E F E F
E E E E
12. SPARQL定义 Definition of SPARQL
RDF Terms(术语)
RDF Term:
RDF
Let I be the set of all IRIs. Let RDF-L be the set of all RDF Literals Let RDF-B be the set of all blank nodes in RDF graphs
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