title: How to assign parameter values in a SparqlParameterizedString
body: <p>I'm playing around some with Dotnetrdf's sparql engine and I'm trying to create parametered queries with no success yet.</p>
  
  <p>Say I'm working on a graph g with a blank node identified as _:1690 with the code</p>
  
  <pre><code>Dim queryString As SparqlParameterizedString = New SparqlParameterizedString()
  queryString.Namespaces.AddNamespace("rdfs", UriFactory.Create("http://www.w3.org/2000/01/rdf-schema#"))
  
  queryString.CommandText = "SELECT ?label { @context rdfs:label ?label } "
  queryString.SetParameter("context", g.GetBlankNode("1690"))
  
  Dim result As VDS.RDF.Query.SparqlResultSet = g.ExecuteQuery(New SparqlQueryParser().ParseFromString(queryString))
  </code></pre>
  
  <p>Whenever I run this, I get all nodes having a rdfs:label property instead of filtering the result on my blank node only.</p>
  
  <p>Please, how to set the parameter's value properly so I get only one item in the result ?</p>
  
  <p>Thanks in advance,
  Max.</p>