public TermCollector(QueryGroup group)
{
itsRequiredTerms = new Hashtable();
itsOptionalTerms = new Hashtable();
itsOptionalNestingDepth = 0;
group.Accept(this);
}
private string GenerateSelect(QueryGroup group)
{
group.Accept(this);
if (itsJoins.Count == 0 && itsWhereTerms.Count == 0)
{
itsIsFeasible = false;
itsIsMappable = false;
return(string.Empty);
}
foreach (Variable variable in itsQuery.Variables)
{
if (itsVariableFirstMentions.Contains(variable.Name))
{
if (!itsSelectedVariables.Contains(variable.Name))
{
itsVariableList.Add(variable);
itsSelectedVariables[variable.Name] = variable;
itsSelectTerms.Add("rn_" + variable.Name + ".resourceHash rh_" + variable.Name);
itsSelectTerms.Add("rn_" + variable.Name + ".nodeHash nh_" + variable.Name);
itsSelectTerms.Add("rn_" + variable.Name + ".nodeType nt_" + variable.Name);
itsJoins.Add("JOIN ResourceNodes rn_" + variable.Name + " ON rn_" + variable.Name + ".resourceHash=" + itsVariableFirstMentions[variable.Name] + " AND rn_" + variable.Name + ".graphId=" + itsVariableTables[variable.Name] + ".graphId");
itsJoins.Add("LEFT OUTER JOIN UriRefs u_" + variable.Name + " ON rn_" + variable.Name + ".nodeHash=u_" + variable.Name + ".hash AND rn_" + variable.Name + ".nodeType='u'");
if (!itsNonLiteralVariables.Contains(variable.Name))
{
itsSelectTerms.Add("COALESCE(u_" + variable.Name + ".uri, pl_" + variable.Name + ".value, l_" + variable.Name + ".value) val_" + variable.Name);
itsSelectTerms.Add("COALESCE(tl_" + variable.Name + ".value, t_" + variable.Name + ".value) sub_" + variable.Name);
itsJoins.Add("LEFT OUTER JOIN PlainLiterals pl_" + variable.Name + " ON rn_" + variable.Name + ".nodeHash=pl_" + variable.Name + ".hash AND rn_" + variable.Name + ".nodeType='p'");
itsJoins.Add("LEFT OUTER JOIN Languages l_" + variable.Name + " ON pl_" + variable.Name + ".languageHash=l_" + variable.Name + ".hash");
itsJoins.Add("LEFT OUTER JOIN TypedLiterals tl_" + variable.Name + " ON rn_" + variable.Name + ".nodehash=tl_" + variable.Name + ".hash AND rn_" + variable.Name + ".nodeType='t'");
itsJoins.Add("LEFT OUTER JOIN DataTypes t_" + variable.Name + " ON tl_" + variable.Name + ".datatypeHash=t_" + variable.Name + ".hash");
}
else
{
itsSelectTerms.Add("u_" + variable.Name + ".uri val_" + variable.Name);
itsSelectTerms.Add("NULL sub_" + variable.Name);
}
}
}
else
{
itsSelectTerms.Add("NULL rh_" + variable.Name);
itsSelectTerms.Add("NULL nh_" + variable.Name);
itsSelectTerms.Add("NULL nt_" + variable.Name);
itsSelectTerms.Add("NULL val_" + variable.Name);
itsSelectTerms.Add("NULL sub_" + variable.Name);
}
}
return(BuildSql());
}