private T ExecuteSeedAggregate <T>(QueryModel queryModel, AggregateFromSeedResultOperator seedAggregate)
{
var projector = ProjectorBuildingExpressionTreeVisitor <T> .BuildAggregateProjector(queryModel, seedAggregate.Func);
var resultItems = LoadData(queryModel);
var result = seedAggregate.GetConstantSeed <T>();
foreach (var item in resultItems)
{
result = projector(item)(result);
}
return(result);
}
private T ExecuteAggregate <T>(QueryModel queryModel, AggregateResultOperator aggregate)
{
var valueProjector = ProjectorBuildingExpressionTreeVisitor <T> .BuildProjector(queryModel);
var funcProjector = ProjectorBuildingExpressionTreeVisitor <T> .BuildAggregateProjector(queryModel, aggregate.Func);
var resultItems = LoadData(queryModel);
if (resultItems.Count == 0)
{
throw new DataException("For aggregate operation at least one result must be used");
}
var result = valueProjector(resultItems[0]);
foreach (var item in resultItems.Skip(1))
{
result = funcProjector(item)(result);
}
return(result);
}
