internal static INode ToSpinRdf(this ISparqlOrderBy ordering, IGraph g, SpinVariableTable varTable)
{
INode o = g.CreateBlankNode();
INode item = null;
do
{
if (item == null)
{
item = g.CreateBlankNode();
}
else
{
INode temp = g.CreateBlankNode();
g.Assert(o, RDF.PropertyRest, temp);
item = temp;
ordering = ordering.Child;
}
g.Assert(o, RDF.PropertyFirst, item);
//TODO: Convert Expression
//g.Assert(o, SP.expression, ordering.E
} while (ordering.Child != null);
return(o);
}
/// <summary>
/// Formats a SPARQL ORDER BY Clause
/// </summary>
/// <param name="orderBy">ORDER BY Clause</param>
/// <returns></returns>
protected virtual String FormatOrderBy(ISparqlOrderBy orderBy)
{
StringBuilder output = new StringBuilder();
if (orderBy.Descending)
{
output.Append("DESC(");
output.Append(this.FormatExpression(orderBy.Expression));
output.Append(')');
}
else
{
output.Append("ASC(");
output.Append(this.FormatExpression(orderBy.Expression));
output.Append(')');
}
if (orderBy.Child != null)
{
output.Append(' ');
output.Append(this.FormatOrderBy(orderBy.Child));
}
return(output.ToString());
}
internal static INode ToSpinRdf(this ISparqlOrderBy ordering, IGraph g, SpinVariableTable varTable)
{
INode o = g.CreateBlankNode();
INode rdfFirst = g.CreateUriNode(new Uri(RdfSpecsHelper.RdfListFirst));
INode rdfRest = g.CreateUriNode(new Uri(RdfSpecsHelper.RdfListRest));
INode rdfNil = g.CreateUriNode(new Uri(RdfSpecsHelper.RdfListNil));
INode expr = g.CreateUriNode(new Uri(SpinPropertyExpression));
INode item = null;
do
{
if (item == null)
{
item = g.CreateBlankNode();
}
else
{
INode temp = g.CreateBlankNode();
g.Assert(o, rdfRest, temp);
item = temp;
ordering = ordering.Child;
}
g.Assert(o, rdfFirst, item);
//TODO: Convert Expression
//g.Assert(o, expr, ordering.E
} while (ordering.Child != null);
return(o);
}
public void ShouldAllowChainingMultipleVariableAndExpressionOrderings()
{
// when
SparqlQuery sparqlQuery = QueryBuilder.SelectAll()
.Where(BuildSPOPattern)
.OrderBy("s")
.OrderByDescending("p")
.OrderBy("o")
.OrderByDescending(expr => expr.Str(expr.Variable("s")))
.OrderBy(expr => expr.Str(expr.Variable("p")))
.OrderByDescending(expr => expr.Str(expr.Variable("o")))
.BuildQuery();
// then
ISparqlOrderBy currentOrdering = sparqlQuery.OrderBy;
for (int i = 0; i < 6; i++)
{
Assert.NotNull(currentOrdering);
currentOrdering = currentOrdering.Child;
}
Assert.Null(currentOrdering);
}
/// <summary>
/// Creates a new Order By clause
/// </summary>
/// <param name="pattern">Pattern</param>
/// <param name="ordering">Ordering</param>
public OrderBy(ISparqlAlgebra pattern, ISparqlOrderBy ordering)
{
this._pattern = pattern;
this._ordering = ordering;
}
/// <summary>
/// Formats a SPARQL ORDER BY Clause
/// </summary>
/// <param name="orderBy">ORDER BY Clause</param>
/// <returns></returns>
protected virtual String FormatOrderBy(ISparqlOrderBy orderBy)
{
StringBuilder output = new StringBuilder();
if (orderBy.Descending)
{
output.Append("DESC(");
output.Append(this.FormatExpression(orderBy.Expression));
output.Append(')');
}
else
{
output.Append("ASC(");
output.Append(this.FormatExpression(orderBy.Expression));
output.Append(')');
}
if (orderBy.Child != null)
{
output.Append(' ');
output.Append(this.FormatOrderBy(orderBy.Child));
}
return output.ToString();
}
/// <summary>
/// Creates a new Order By clause
/// </summary>
/// <param name="pattern">Pattern</param>
/// <param name="ordering">Ordering</param>
public OrderBy(ISparqlAlgebra pattern, ISparqlOrderBy ordering)
{
this._pattern = pattern;
this._ordering = ordering;
}
