private static T GetAggregationValue <T>(Expression expression, IReadOnlyCollection <Dictionary <string, object> > dataCollection)
{
var methodName = RepositoryExpressionUtilities.GetMethodName(expression);
var columnName = RepositoryExpressionUtilities.GetAggregationColumnName(methodName);
return(GetAggregationValue <T>(columnName, dataCollection));
}
private static T GetAnyValue <T>(IReadOnlyCollection <Dictionary <string, object> >
dataCollection)
{
var columnName = RepositoryExpressionUtilities.GetAnyColumnName();
var count = GetAggregationValue <int>(columnName, dataCollection);
var value = count > 0;
if (value is T typedValue)
{
return(typedValue);
}
return(default(T));
}
private T ExecuteScalar <T>(Expression expression)
{
var chain = ExpressionToMetadataConverter.Convert(expression, _elementType);
var dataCollection = LoadDataCollection(chain);
if (RepositoryExpressionUtilities.IsAggregationMethodExpression(expression))
{
return(GetAggregationValue <T>(expression, dataCollection));
}
if (RepositoryExpressionUtilities.IsAnyMethodExpression(expression))
{
return(GetAnyValue <T>(dataCollection));
}
var models = LoadModelCollection(dataCollection, chain);
return(ApplyScalarProjector <T>(models.ToList <object>(), chain));
}