%META:TOPICPARENT{name="VirtTipsAndTricksSPARQL11FeaturesExamplesCollection"}%

---+ Virtuoso SPARQL 1.1. NOT EXISTS and MINUS 

---++What?
This guide contains example queries using SPARQL 1.1 <code>NOT EXISTS</code> and <code>MINUS</code>, which you should be able to run against any SPARQL 1.1 endpoint.

---++Why?
<code>NOT EXISTS</code> and <code>MINUS</code> offer flexible ways to check for the absence of a given pattern, or to exclude possible solutions from the result set.

---++How?

Here are some examples showcasing Virtuoso's support for this functionality:


---+++NOT EXISTS

<verbatim>
SELECT COUNT(*) 
WHERE 
  {
    ?s ?p "Novosibirsk"  
    FILTER 
      NOT EXISTS { ?s ?p "???????????" } 
  }
</verbatim>
   * [[http://bit.ly/WCQsvi][View the SPARQL Query Definition via SPARQL Protocol URL]]
   * [[http://bit.ly/16GYhmC][View the SPARQL Query Results via SPARQL Protocol URL]]

---+++MINUS
<verbatim> 
SELECT COUNT(*) 
WHERE 
  { 
    { ?s ?p "Novosibirsk" } 
    MINUS 
    { ?s ?p "???????????" }
  }
</verbatim> 
   * [[http://bit.ly/XZTlID][View the SPARQL Query Definition via SPARQL Protocol URL]]
   * [[http://bit.ly/ZH6VfM][View the SPARQL Query Results via SPARQL Protocol URL]]


---++Related

   * [[http://www.w3.org/TR/sparql11-query/#neg-notexists-minus][SPARQL 1.1. -- Relationship and differences between NOT EXISTS and MINUS]]
   * [[VirtTipsAndTricksGuide][Virtuoso Tips and Tricks Collection]]
   * [[VirtTipsAndTricksSPARQL11FeaturesExamplesCollection][Virtuoso SPARQL 1.1 Usage Examples Collection]]
   * [[http://virtuoso.openlinksw.com/tutorials/sparql/SPARQL_Tutorials_Part_9/SPARQL_Tutorials_Part_9.html][Virtuoso SPARQL 1.1 Syntax Tutorial]]