/// <summary>
/// Computes a time-sensitive maximum aggregate using "snapshot windows" (SI terminology).
/// </summary>
public IAggregate <TSource, MinMaxState <TValue>, TValue> Max <TValue>(Expression <Func <TSource, TValue> > selector)
{
Invariant.IsNotNull(selector, nameof(selector));
if (this.Properties.IsConstantDuration)
{
var aggregate = new FixedIntervalMaxAggregate <TValue>(this.Properties.QueryContainer);
return(aggregate.SkipNulls().Wrap(selector).ApplyFilter(this.Filter));
}
else
{
var aggregate = new MaxAggregate <TValue>(this.Properties.QueryContainer);
return(aggregate.SkipNulls().Wrap(selector).ApplyFilter(this.Filter));
}
}
public AggregateExpression Max(SparqlExpression expression)
{
var aggregate = new MaxAggregate(expression.Expression, _distinctAggregate);
return(new AggregateExpression(aggregate));
}
public AggregateExpression Max(VariableTerm variable)
{
var aggregate = new MaxAggregate(variable, _distinctAggregate);
return(new AggregateExpression(aggregate));
}
internal static List <Entity> ProcessAggregateFetchXml(XrmFakedContext ctx, XDocument xmlDoc, List <Entity> resultOfQuery)
{
// Validate that <all-attributes> is not present,
// that all attributes have groupby or aggregate, and an alias,
// and that there is exactly 1 groupby.
if (RetrieveFetchXmlNode(xmlDoc, "all-attributes") != null)
{
throw new Exception("Can't have <all-attributes /> present when using aggregate");
}
var ns = xmlDoc.Root.Name.Namespace;
var entityName = RetrieveFetchXmlNode(xmlDoc, "entity")?.GetAttribute("name")?.Value;
if (string.IsNullOrEmpty(entityName))
{
throw new Exception("Can't find entity name for aggregate query");
}
var aggregates = new List <FetchAggregate>();
var groups = new List <FetchGrouping>();
foreach (var attr in xmlDoc.Descendants(ns + "attribute"))
{
//TODO: Find entity alias. Handle aliasedvalue in the query result.
var alias = attr.GetAttribute("alias")?.Value;
var logicalName = attr.GetAttribute("name")?.Value;
if (string.IsNullOrEmpty("alias"))
{
throw new Exception("Missing alias for attribute in aggregate fetch xml");
}
if (string.IsNullOrEmpty("name"))
{
throw new Exception("Missing name for attribute in aggregate fetch xml");
}
if (attr.IsAttributeTrue("groupby"))
{
var dategrouping = attr.GetAttribute("dategrouping")?.Value;
if (dategrouping != null)
{
DateGroupType t;
if (!Enum.TryParse(dategrouping, true, out t))
{
throw new Exception("Unknown dategrouping value '" + dategrouping + "'");
}
groups.Add(new DateTimeGroup()
{
Type = t,
OutputAlias = alias,
Attribute = logicalName
});
}
else
{
groups.Add(new SimpleValueGroup()
{
OutputAlias = alias,
Attribute = logicalName
});
}
}
else
{
var agrFn = attr.GetAttribute("aggregate")?.Value;
if (string.IsNullOrEmpty(agrFn))
{
throw new Exception("Attributes must have be aggregated or grouped by when using aggregation");
}
FetchAggregate newAgr = null;
switch (agrFn?.ToLower())
{
case "count":
newAgr = new CountAggregate();
break;
case "countcolumn":
if (attr.IsAttributeTrue("distinct"))
{
newAgr = new CountDistinctAggregate();
}
else
{
newAgr = new CountColumnAggregate();
}
break;
case "min":
newAgr = new MinAggregate();
break;
case "max":
newAgr = new MaxAggregate();
break;
case "avg":
newAgr = new AvgAggregate();
break;
case "sum":
newAgr = new SumAggregate();
break;
default:
throw new Exception("Unknown aggregate function '" + agrFn + "'");
}
newAgr.OutputAlias = alias;
newAgr.Attribute = logicalName;
aggregates.Add(newAgr);
}
}
List <Entity> aggregateResult;
if (groups.Any())
{
aggregateResult = ProcessGroupedAggregate(entityName, resultOfQuery, aggregates, groups);
}
else
{
aggregateResult = new List <Entity>();
var ent = ProcessAggregatesForSingleGroup(entityName, resultOfQuery, aggregates);
aggregateResult.Add(ent);
}
return(OrderAggregateResult(xmlDoc, aggregateResult.AsQueryable()));
}
public override void SetObjectOperator(ResultOperatorBase resultOperator)
{
base.SetObjectOperator(resultOperator);
if (ObjectVariable != null)
{
if (resultOperator is AnyResultOperator)
{
// When using x.Any(), we add a LIMIT 1 the query results in the SparqlQueryGenerator.
// When using .Any(x => ..), the variable x is locally scoped and cannot be
// used in outer queries. Therefore do not need to actually select it.
// This avoids issues with Stardog:
// https://community.stardog.com/t/sparql-union-only-working-with-inferencing-enabled/1040/9
}
else if (resultOperator is AverageResultOperator)
{
var aggregate = new AverageAggregate(new VariableTerm(ObjectVariable.Name));
SetObjectVariable(aggregate.AsSparqlVariable(), true);
}
else if (resultOperator is CountResultOperator)
{
var aggregate = new CountDistinctAggregate(new VariableTerm(ObjectVariable.Name));
SetObjectVariable(aggregate.AsSparqlVariable(), true);
}
else if (resultOperator is FirstResultOperator)
{
// "Using LIMIT and OFFSET to select different subsets of the query solutions
// will not be useful unless the order is made predictable by using ORDER BY."
// Source: https://www.w3.org/TR/2013/REC-sparql11-query-20130321/#modOffset
// Therefore, if no ordering exists we add an ordering on the current subject
// to make the query result predictable.
if (!QueryModel.BodyClauses.OfType <OrderByClause>().Any())
{
OrderBy(SubjectVariable);
}
else
{
// In case the order was make explicit, we have to do nothing.
}
Limit(1);
}
else if (resultOperator is LastResultOperator)
{
// "Using LIMIT and OFFSET to select different subsets of the query solutions
// will not be useful unless the order is made predictable by using ORDER BY."
// Source: https://www.w3.org/TR/2013/REC-sparql11-query-20130321/#modOffset
// Therefore, if no ordering exists we add an ordering on the current subject
// to make the query result predictable.
if (!QueryModel.BodyClauses.OfType <OrderByClause>().Any())
{
OrderByDescending(SubjectVariable);
}
else
{
// Inverting the direction of the first ordering is handled in SparqlQueryModelVisitor.VisitOrdering().
// This is because the orderings are not necessarily processed *before* the result operators..
}
Limit(1);
}
else if (resultOperator is MaxResultOperator)
{
var aggregate = new MaxAggregate(new VariableTerm(ObjectVariable.Name));
SetObjectVariable(aggregate.AsSparqlVariable(), true);
}
else if (resultOperator is MinResultOperator)
{
var aggregate = new MinAggregate(new VariableTerm(ObjectVariable.Name));
SetObjectVariable(aggregate.AsSparqlVariable(), true);
}
else if (resultOperator is SumResultOperator)
{
var aggregate = new SumAggregate(new VariableTerm(ObjectVariable.Name));
SetObjectVariable(aggregate.AsSparqlVariable(), true);
}
else if (resultOperator is OfTypeResultOperator)
{
OfTypeResultOperator ofType = resultOperator as OfTypeResultOperator;
RdfClassAttribute type = ofType.SearchedItemType.TryGetCustomAttribute <RdfClassAttribute>();
if (type == null)
{
throw new ArgumentException("No RdfClass attrribute declared on type: " + ofType.SearchedItemType);
}
SparqlVariable s = ObjectVariable;
SparqlVariable p = VariableGenerator.CreatePredicateVariable();
SparqlVariable o = VariableGenerator.CreateObjectVariable();
WhereResource(s, p, o);
WhereResourceOfType(o, ofType.SearchedItemType);
}
else if (resultOperator is SkipResultOperator)
{
SkipResultOperator op = resultOperator as SkipResultOperator;
Offset(int.Parse(op.Count.ToString()));
}
else if (resultOperator is TakeResultOperator)
{
TakeResultOperator op = resultOperator as TakeResultOperator;
Limit(int.Parse(op.Count.ToString()));
}
else
{
throw new NotImplementedException(resultOperator.ToString());
}
}
}