Virtuoso's RDF support includes in-built support for the SPARQL query language. It also includes a number of powerful extensions that cover path traversal and business intelligence features. In addition, there is in-built security based on Virtuoso's support for Row Level policy based security, custom authentication, and Named Graphs.
The current implementation does not support some SPARQL features.
On the other hand, Virtuoso implements some extensions to SPARQL:
The following dump is BNF grammar of SPARQL with all Virtuoso extensions, but without rules for syntax of lexems. Rule numbers in square brackets are from W3C normative SPARQL grammar, asterisk means that the rule differs from W3C grammar due to Virtuoso extensions, [Virt] means that the rule is Virtuoso-specific. [DML] stands for data manipulation language extensions from SPARUL.
[1]* Query ::= Prolog ( QueryBody | SparulAction* | ( QmStmt ('.' QmStmt)* '.'? ) )
[1] QueryBody ::= SelectQuery | ConstructQuery | DescribeQuery | AskQuery
[2]* Prolog ::= Define* BaseDecl? PrefixDecl*
[Virt] Define ::= 'DEFINE' QNAME (QNAME | Q_IRI_REF | String )
[3] BaseDecl ::= 'BASE' Q_IRI_REF
[4] PrefixDecl ::= 'PREFIX' QNAME_NS Q_IRI_REF
[5]* SelectQuery ::= 'SELECT' 'DISTINCT'? ( ( Retcol ( ','? Retcol )* ) | '*' )
DatasetClause* WhereClause SolutionModifier
[6] ConstructQuery ::= 'CONSTRUCT' ConstructTemplate DatasetClause* WhereClause SolutionModifier
DatasetClause* WhereClause? SolutionModifier
[8] AskQuery ::= 'ASK' DatasetClause* WhereClause
[9] DatasetClause ::= 'FROM' ( DefaultGraphClause | NamedGraphClause )
[10]* DefaultGraphClause ::= SourceSelector SpongeOptionList?
[11]* NamedGraphClause ::= 'NAMED' SourceSelector SpongeOptionList?
[Virt] SpongeOptionList ::= 'OPTION' '(' ( SpongeOption ( ',' SpongeOption )* )? ')'
[Virt] SpongeOption ::= QNAME PrecodeExpn
[Virt] PrecodeExpn ::= Expn (* Only global variables can occur in Expn, local can not *)
[13] WhereClause ::= 'WHERE'? GroupGraphPattern
[14] SolutionModifier ::= OrderClause?
((LimitClause OffsetClause?) | (OffsetClause LimitClause?))?
[15] OrderClause ::= 'ORDER' 'BY' OrderCondition+
[16]* OrderCondition ::= ( 'ASC' | 'DESC' )?
( FunctionCall | Var | ( '(' Expn ')' ) | ( '[' Expn ']' ) )
[17] LimitClause ::= 'LIMIT' INTEGER
[17] LimitClause ::= 'LIMIT' INTEGER
[18] OffsetClause ::= 'OFFSET' INTEGER
[18] OffsetClause ::= 'OFFSET' INTEGER
[19]* GroupGraphPattern ::= '{' ( GraphPattern | SelectQuery ) '}'
[20] GraphPattern ::= Triples? ( GraphPatternNotTriples '.'? GraphPattern )?
[21]* GraphPatternNotTriples ::=
QuadMapGraphPattern
| OptionalGraphPattern
| GroupOrUnionGraphPattern
| GraphGraphPattern
| Constraint
[22] OptionalGraphPattern ::= 'OPTIONAL' GroupGraphPattern
[Virt] QuadMapGraphPattern ::= 'QUAD' 'MAP' ( IRIref | '*' ) GroupGraphPattern
[23] GraphGraphPattern ::= 'GRAPH' VarOrBlankNodeOrIRIref GroupGraphPattern
[24] GroupOrUnionGraphPattern ::= GroupGraphPattern ( 'UNION' GroupGraphPattern )*
[25]* Constraint ::= 'FILTER' ( ( '(' Expn ')' ) | BuiltInCall | FunctionCall )
[26]* ConstructTemplate ::= '{' ConstructTriples '}'
[27] ConstructTriples ::= ( Triples1 ( '.' ConstructTriples )? )?
[28] Triples ::= Triples1 ( '.' Triples? )?
[29] Triples1 ::= VarOrTerm PropertyListNotEmpty | TriplesNode PropertyList
[30] PropertyList ::= PropertyListNotEmpty?
[31] PropertyListNotEmpty ::= Verb ObjectList ( ';' PropertyList )?
[32]* ObjectList ::= ObjGraphNode ( ',' ObjectList )?
[Virt] ObjGraphNode ::= GraphNode TripleOptions?
[Virt] TripleOptions ::= 'OPTION' '(' TripleOption ( ',' TripleOption )? ')'
[Virt] TripleOption ::= 'INFERENCE' ( QNAME | Q_IRI_REF | SPARQL_STRING )
[33] Verb ::= VarOrBlankNodeOrIRIref | 'a'
[34] TriplesNode ::= Collection | BlankNodePropertyList
[35] BlankNodePropertyList ::= '[' PropertyListNotEmpty ']'
[36] Collection ::= '(' GraphNode* ')'
[37] GraphNode ::= VarOrTerm | TriplesNode
[38] VarOrTerm ::= Var | GraphTerm
[39]* VarOrIRIrefOrBackquoted ::= Var | IRIref | Backquoted
[40]* VarOrBlankNodeOrIRIrefOrBackquoted ::= Var | BlankNode | IRIref | Backquoted
[Virt] Retcol ::= ( Var | ( '(' Expn ')' ) | RetAggCall ) ( 'AS' ( VAR1 | VAR2 ) )?
[Virt] RetAggCall ::= AggName '(', ( '*' | ( 'DISTINCT'? Var ) ) ')'
[Virt] AggName ::= 'COUNT' | 'AVG' | 'MIN' | 'MAX' | 'SUM'
[41]* Var ::= VAR1 | VAR2 | GlobalVar | ( Var ( '+>' | '*>' ) IRIref )
[Virt] GlobalVar ::= QUEST_COLON_PARAMNAME | DOLLAR_COLON_PARAMNAME
| QUEST_COLON_PARAMNUM | DOLLAR_COLON_PARAMNUM
[42]* GraphTerm ::= IRIref | RDFLiteral | ( '-' | '+' )? NumericLiteral
| BooleanLiteral | BlankNode | NIL | Backquoted
[Virt] Backquoted ::= '`' Expn '`'
[43] Expn ::= ConditionalOrExpn
[44] ConditionalOrExpn ::= ConditionalAndExpn ( '||' ConditionalAndExpn )*
[45] ConditionalAndExpn ::= ValueLogical ( '&&' ValueLogical )*
[46] ValueLogical ::= RelationalExpn
[47]* RelationalExpn ::= NumericExpn
( ( ('='|'!='|'<'|'>'|'<='|'>='|'LIKE') NumericExpn )
| ( 'IN' '(' Expns ')' ) )?
[49] AdditiveExpn ::= MultiplicativeExpn ( ('+'|'-') MultiplicativeExpn )*
[50] MultiplicativeExpn ::= UnaryExpn ( ('*'|'/') UnaryExpn )*
[51] UnaryExpn ::= ('!'|'+'|'-')? PrimaryExpn
[58] PrimaryExpn ::=
BracketedExpn | BuiltInCall | IRIrefOrFunction
| RDFLiteral | NumericLiteral | BooleanLiteral | BlankNode | Var
[55] IRIrefOrFunction ::= IRIref ArgList?
[52]* BuiltInCall ::=
( 'STR' '(' Expn ')' )
| ( 'IRI' '(' Expn ')' )
| ( 'LANG' '(' Expn ')' )
| ( 'LANGMATCHES' '(' Expn ',' Expn ')' )
| ( 'DATATYPE' '(' Expn ')' )
| ( 'BOUND' '(' Var ')' )
| ( 'sameTERM' '(' Expn ',' Expn ')' )
| ( 'isIRI' '(' Expn ')' )
| ( 'isURI' '(' Expn ')' )
| ( 'isBLANK' '(' Expn ')' )
| ( 'isLITERAL' '(' Expn ')' )
| RegexExpn
[53] RegexExpn ::= 'REGEX' '(' Expn ',' Expn ( ',' Expn )? ')'
[54] FunctionCall ::= IRIref ArgList
[56]* ArgList ::= ( NIL | '(' Expns ')' )
[Virt] Expns ::= Expn ( ',' Expn )*
[59] NumericLiteral ::= INTEGER | DECIMAL | DOUBLE
[60] RDFLiteral ::= String ( LANGTAG | ( '^^' IRIref ) )?
[61] BooleanLiteral ::= 'true' | 'false'
[63] IRIref ::= Q_IRI_REF | QName
[64] QName ::= QNAME | QNAME_NS
[65]* BlankNode ::= BLANK_NODE_LABEL | ( '[' ']' )
[DML] SparulAction ::=
CreateAction | DropAction | LoadAction
| InsertAction | InsertDataAction | DeleteAction | DeleteDataAction
| ModifyAction | ClearAction
[DML]* InsertAction ::=
'INSERT' ( ( 'IN' | 'INTO ) 'GRAPH' ( 'IDENTIFIED' 'BY' )? )? PrecodeExpn
ConstructTemplate ( DatasetClause* WhereClause SolutionModifier )?
[DML]* InsertDataAction ::=
'INSERT' 'DATA' ( ( 'IN' | 'INTO ) 'GRAPH' ( 'IDENTIFIED' 'BY' )? )?
PrecodeExpn ConstructTemplate
[DML]* DeleteAction ::=
'DELETE' ( 'FROM' 'GRAPH' ( 'IDENTIFIED' 'BY' )? )? PrecodeExpn
ConstructTemplate ( DatasetClause* WhereClause SolutionModifier )?
[DML]* DeleteDataAction ::=
'DELETE' 'DATA' ( 'FROM' 'GRAPH' ( 'IDENTIFIED' 'BY' )? )?
PrecodeExpn ConstructTemplate
[DML]* ModifyAction ::=
'MODIFY' ( 'GRAPH' ( 'IDENTIFIED' 'BY' )? PrecodeExpn?
'DELETE' ConstructTemplate 'INSERT' ConstructTemplate
( DatasetClause* WhereClause SolutionModifier )?
[DML]* ClearAction ::= 'CLEAR' ( 'GRAPH' ( 'IDENTIFIED' 'BY' )? PrecodeExpn )?
[DML]* LoadAction ::= 'LOAD' PrecodeExpn
( ( 'IN' | 'INTO' ) 'GRAPH' ( 'IDENTIFIED' 'BY' )? PrecodeExpn )?
[DML]* CreateAction ::= 'CREATE' 'SILENT'? 'GRAPH' ( 'IDENTIFIED' 'BY' )? PrecodeExpn
[DML]* DropAction ::= 'DROP' 'SILENT'? 'GRAPH' ( 'IDENTIFIED' 'BY' )? PrecodeExpn
[Virt] QmStmt ::= QmSimpleStmt | QmCreateStorage | QmAlterStorage
[Virt] QmSimpleStmt ::=
QmCreateIRIClass | QmCreateLiteralClass | QmDropIRIClass | QmDropLiteralClass
| QmCreateIRISubclass | QmDropQuadStorage | QmDropQuadMap
[Virt] QmCreateIRIClass ::= 'CREATE' 'IRI' 'CLASS' QmIRIrefConst
( ( String QmSqlfuncArglist )
| ( 'USING' QmSqlfuncHeader ',' QmSqlfuncHeader ) )
[Virt] QmCreateLiteralClass ::= 'CREATE' 'LITERAL' 'CLASS' QmIRIrefConst
'USING' QmSqlfuncHeader ',' QmSqlfuncHeader QmLiteralClassOptions?
[Virt] QmDropIRIClass ::= 'DROP' 'IRI' 'CLASS' QmIRIrefConst
[Virt] QmDropLiteralClass ::= 'DROP' 'LITERAL' 'CLASS' QmIRIrefConst
[Virt] QmCreateIRISubclass ::= 'IRI' 'CLASS' QmIRIrefConst 'SUBCLASS' 'OF' QmIRIrefConst
[Virt] QmIRIClassOptions ::= 'OPTION' '(' QmIRIClassOption (',' QmIRIClassOption)* ')'
[Virt] QmIRIClassOption ::=
'BIJECTION'
| 'DEREF'
| 'RETURNS' STRING ('UNION' STRING)*
[Virt] QmLiteralClassOptions ::= 'OPTION' '(' QmLiteralClassOption (',' QmLiteralClassOption)* ')'
[Virt] QmLiteralClassOption ::=
( 'DATATYPE' QmIRIrefConst )
| ( 'LANG' STRING )
| ( 'LANG' STRING )
| 'BIJECTION'
| 'DEREF'
| 'RETURNS' STRING ('UNION' STRING)*
[Virt] QmCreateStorage ::= 'CREATE' 'QUAD' 'STORAGE' QmIRIrefConst QmSourceDecl* QmMapTopGroup
[Virt] QmAlterStorage ::= 'ALTER' 'QUAD' 'STORAGE' QmIRIrefConst QmSourceDecl* QmMapTopGroup
[Virt] QmDropStorage ::= 'DROP' 'QUAD' 'STORAGE' QmIRIrefConst
[Virt] QmDropQuadMap ::= 'DROP' 'QUAD' 'MAP' 'GRAPH'? QmIRIrefConst
[Virt] QmDrop ::= 'DROP' 'GRAPH'? QmIRIrefConst
[Virt] QmSourceDecl ::=
( 'FROM' QTABLE 'AS' PLAIN_ID QmTextLiteral* )
| ( 'FROM' PLAIN_ID 'AS' PLAIN_ID QmTextLiteral* )
| QmCondition
[Virt] QmTextLiteral ::= 'TEXT' 'XML'? 'LITERAL' QmSqlCol ( 'OF' QmSqlCol )? QmTextLiteralOptions?
[Virt] QmTextLiteralOptions ::= 'OPTION' '(' QmTextLiteralOption ( ',' QmTextLiteralOption )* ')'
[Virt] QmMapTopGroup ::= '{' QmMapTopOp ( '.' QmMapTopOp )* '.'? '}'
[Virt] QmMapTopOp ::= QmMapOp | QmDropQuadMap | QmDrop
[Virt] QmMapGroup ::= '{' QmMapOp ( '.' QmMapOp )* '.'? '}'
[Virt] QmMapOp ::=
( 'CREATE' QmIRIrefConst 'AS' QmMapIdDef )
| ( 'CREATE' 'GRAPH'? QmIRIrefConst 'USING' 'STORAGE' QmIRIrefConst QmOptions? )
| ( QmNamedField+ QmOptions? QmMapGroup )
| QmTriples1
[Virt] QmMapIdDef ::= QmMapTriple | ( QmNamedField+ QmOptions? QmMapGroup )
[Virt] QmMapTriple ::= QmFieldOrBlank QmVerb QmObjField
[Virt] QmTriples1 ::= QmFieldOrBlank QmProps
[Virt] QmNamedField ::= ('GRAPH'|'SUBJECT'|'PREDICATE'|'OBJECT') QmField
[Virt] QmProps ::= QmProp ( ';' QmProp )?
[Virt] QmProp ::= QmVerb QmObjField ( ',' QmObjField )*
[Virt] QmObjField ::= QmFieldOrBlank QmCondition* QmOptions?
[Virt] QmIdSuffix ::= 'AS' QmIRIrefConst
[Virt] QmVerb ::= QmField | ( '[' ']' ) | 'a'
[Virt] QmFieldOrBlank ::= QmField | ( '[' ']' )
[Virt] QmField ::=
NumericLiteral
| RdfLiteral
| ( QmIRIrefConst ( '(' ( QmSqlCol ( ',' QmSqlCol )* )? ')' )? )
| QmSqlCol
[Virt] QmCondition ::= 'WHERE' ( ( '(' SQLTEXT ')' ) | String )
[Virt] QmOptions ::= 'OPTION' '(' QmOption ( ',' QmOption )* ')'
[Virt] QmOption ::= ( 'SOFT'? 'EXCLUSIVE' ) | ( 'ORDER' INTEGER ) | ( 'USING' PLAIN_ID )
[Virt] QmSqlfuncHeader ::= 'FUNCTION' SQL_QTABLECOLNAME QmSqlfuncArglist 'RETURNS' QmSqltype
[Virt] QmSqlfuncArglist ::= '(' ( QmSqlfuncArg ( ',' QmSqlfuncArg )* )? ')'
[Virt] QmSqlfuncArg ::= ('IN' | QmSqlId) QmSqlId QmSqltype
[Virt] QmSqltype ::= QmSqlId ( 'NOT' 'NULL' )?
[Virt] QmSqlCol ::= QmSqlId | spar_qm_sql_id
[Virt] QmSqlId ::= PLAIN_ID | 'TEXT' | 'XML'
[Virt] QmIRIrefConst ::= IRIref | ( 'IRI' '(' String ')' )
Example using OFFSET and LIMIT:
Virtuoso uses a zero index in the OFFSET. Thus in the example below, will be taken position at record 9000 in the result set, and will get the next 1000 rows starting from 9001 record. Note that the MaxSortedTopRows in parameters Virtuoso ini section needs to be encreased (default is 10000).
select ?name ORDER BY ?name OFFSET 9000 LIMIT 1000
In the current implementation, the XQuery Core Function Library is not available from SPARQL.
As a temporary workaround, string parsing functions are made available, because they are widely used in W3C DAWG examples and the like. They are:
xsd:boolean (in strg any) returns integer xsd:dateTime (in strg any) returns datetime xsd:double (in strg varchar) returns double precision xsd:float (in strg varchar) returns float xsd:integer (in strg varchar) returns integer
(assuming that the query contains declaration 'PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>')
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