public void SetUp()
{
_querySource = ExpressionHelper.CreateMainFromClause_Int();
_sourceExpression = new QuerySourceReferenceExpression(_querySource);
_func = CreateFunc <int, int, int> ((total, i) => total + i);
_resultOperator = new AggregateResultOperator(_func);
}
public void GetOutputDataInfo_Covariant()
{
var func = CreateFunc <IComparable, IComparable, string> ((i1, i2) => null);
var resultOperator = new AggregateResultOperator(func);
var itemExpression = Expression.Constant("test");
var input = new StreamedSequenceInfo(typeof(string[]), itemExpression);
var result = resultOperator.GetOutputDataInfo(input);
Assert.That(result, Is.InstanceOf(typeof(StreamedScalarValueInfo)));
Assert.That(result.DataType, Is.SameAs(typeof(string)));
}
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);
}