Develop Reference

Create query by dynamically pass the GroupBy() and create new class in Select() using Expression tree

I`m having simple method which builds IQueryable and returns it.
public IQueryable<ClassDTO> ReportByNestedProperty()
{
IQueryable<Class> query = this.dbSet;
IQueryable<ClassDTO> groupedQuery =
from opportunity in query
group new
{
ItemGroup = opportunity.OpportunityStage.Name,
EstimatedRevenue = opportunity.EstimatedRevenue,
CostOfLead = opportunity.CostOfLead
}
by new
{
opportunity.OpportunityStage.Name,
opportunity.OpportunityStage.Id
}
into item
select new ClassDTO()
{
ItemGroup = string.IsNullOrEmpty(item.Key.Name) ? "[Not Assigned]" : item.Key.Name,
Count = item.Select(z => z.ItemGroup.Name).Count(), // int
Commission = item.Sum(z => z.EstimatedRevenue), // decimal
Cost = item.Sum(z => z.CostOfLead), // decimal?
};
return groupedQuery;
}
This is fine. The thing i need is to create method with same return type, but groupby by different prperties dynamically. So from the above code I want to have 3 dynamic parts which will be passed as params:
ItemGroup = opportunity.OpportunityStage.Name
and
by new
{
opportunity.OpportunityStage.Name,
opportunity.OpportunityStage.Id
}
So the new method should be like this
public IQueryable<ClassDTO> ReportByNestedProperty(string firstNestedGroupByProperty, string secondNestedGroupByProperty)
{
// TODO: ExpressionTree
}
And call it like this:
ReportByNestedProperty("OpportunityStage.Name","OpportunityStage.Id")
ReportByNestedProperty("OtherNestedProperty.Name","OtherNestedProperty.Id")
ReportByNestedProperty("OpportunityStage.Name","OpportunityStage.Price")
So the main thing is to create expressions with these two selects:
opportunity.OpportunityStage.Name,
opportunity.OpportunityStage.Id
I have tried toe create the select expressions, groupby, the creation of Anonomoys classes and the DTO Class but I just cant get it right.
EDIT:
Here are the classes involved:
public class ClassDTO
{
public ClassDTO() { }
[Key]
public string ItemGroup { get; set; }
public decimal Commission { get; set; }
public decimal? Cost { get; set; }
public int Count { get; set; }
}
Class obj is a pretty big one so i`m posting just part of it
public partial class Class
{
public Class() { }
[Key]
public Guid Id { get; set; }
public Guid? OpportunityStageId { get; set; }
[ForeignKey(nameof(OpportunityStageId))]
[InverseProperty(nameof(Entities.OpportunityStage.Class))]
public virtual OpportunityStage OpportunityStage { get; set; }
}
public partial class OpportunityStage
{
public OpportunityStage()
{
this.Classes = new HashSet<Class>();
}
[Key]
public Guid Id { get; set; }
public string Name { get; set; }
[InverseProperty(nameof(Class.OpportunityStage))]
public virtual ICollection<TruckingCompanyOpportunity> Classes{ get; set; }
}

I have simplified your Grouping query and introduced private class IdName which should replace anonymous class usage:
class IdName
{
public int Id { get; set; }
public string Name { get; set; } = null!;
}
static Expression MakePropPath(Expression objExpression, string path)
{
return path.Split('.').Aggregate(objExpression, Expression.PropertyOrField);
}
IQueryable<ClassDTO> ReportByNestedProperty(IQueryable<Class> query, string nameProperty, string idProperty)
{
// Let compiler to do half of the work
Expression<Func<Class, string, int, IdName>> keySelectorTemplate = (opportunity, name, id) =>
new IdName { Name = name, Id = id };
var param = keySelectorTemplate.Parameters[0];
// generating expressions from prop path
var nameExpr = MakePropPath(param, nameProperty);
var idExpr = MakePropPath(param, idProperty);
var body = keySelectorTemplate.Body;
// substitute parameters
body = ReplacingExpressionVisitor.Replace(keySelectorTemplate.Parameters[1], nameExpr, body);
body = ReplacingExpressionVisitor.Replace(keySelectorTemplate.Parameters[2], idExpr, body);
var keySelectorLambda = Expression.Lambda<Func<Class, IdName>>(body, param);
// finalize query
IQueryable<ClassDTO> groupedQuery = query
.GroupBy(keySelectorLambda)
.Select(item => new ClassDTO()
{
ItemGroup = string.IsNullOrEmpty(item.Key.Name) ? "[Not Assigned]" : item.Key.Name,
Count = item.Count(x => x.Name), // int
Commission = item.Sum(x => x.EstimatedRevenue), // decimal
Cost = item.Sum(x => x.CostOfLead), // decimal?
});
return groupedQuery;
}

Resampling with Deedle duplicate keys

My code below resamples 5-minute interval to 1-day interval for the daily profit stats. The problem is that BacktestResult consists of duplicate CloseDate values, because I'm testing with multiple pairs (TRXUSDT, ETHUSDT and BTCUSDT). dailyProfit returns Series<DateTime, double>, which explains the exception. How can I make it grouped by Pair or something? It works fine when tested with one pair.
// Create series
var series = _backtestResults.ToOrdinalSeries();
// daily_profit = results.resample('1d', on = 'close_date')['profit_percent'].sum()
var dailyProfit = series.ResampleEquivalence(
index => new DateTime(series[index].CloseDate.Year, series[index].CloseDate.Month, series[index].CloseDate.Day, 0, 0, 0, DateTimeKind.Utc),
group => group.SelectValues(g => g.ProfitPercentage).Sum()).DropMissing();
// classes
public class BacktestResult
{
public string Pair { get; set; }
public decimal ProfitPercentage { get; set; }
public decimal ProfitAbs { get; set; }
public decimal OpenRate { get; set; }
public decimal CloseRate { get; set; }
public DateTime OpenDate { get; set; }
public DateTime CloseDate { get; set; }
public decimal OpenFee { get; set; }
public decimal CloseFee { get; set; }
public decimal Amount { get; set; }
public decimal TradeDuration { get; set; }
public SellType SellReason { get; set; }
}
Edit:
Example which takes the JSON data from pastebin:
using Deedle;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
namespace Resample
{
class Program
{
public class BacktestResultTest
{
public string Pair { get; set; }
public decimal ProfitPercentage { get; set; }
public decimal ProfitAbs { get; set; }
public decimal OpenRate { get; set; }
public decimal CloseRate { get; set; }
public DateTime OpenDate { get; set; }
public DateTime CloseDate { get; set; }
public decimal OpenFee { get; set; }
public decimal CloseFee { get; set; }
public decimal Amount { get; set; }
public decimal TradeDuration { get; set; }
public bool OpenAtEnd { get; set; }
public int SellReason { get; set; }
}
static void Main(string[] args)
{
// Take JSON data from pastebin
using var webClient = new WebClient();
var json = webClient.DownloadString("https://pastebin.com/raw/Dhp9202f");
// Deserialize the data
var data = JsonConvert.DeserializeObject<List<BacktestResultTest>>(json);
var ts = data.ToOrdinalSeries();
var byDateAndPair = ts.SelectKeys(kvp => Tuple.Create(kvp.Value.Value.CloseDate, kvp.Value.Value.Pair)).SortByKey();
// daily_profit = results.resample('1d', on = 'close_date')['profit_percent'].sum()
var dailyProfit2 = byDateAndPair.ResampleEquivalence(
k => Tuple.Create(new DateTime(k.Item1.Year, k.Item1.Month, k.Item1.Day), k.Item2),
g => g.Select(kvp => kvp.Value.ProfitPercentage).Sum());
// backtest_worst_day = min(daily_profit)
var worstDay2 = dailyProfit2.Min();
// backtest_best_day = max(daily_profit)
var bestDay2 = dailyProfit2.Max();
// winning_days = sum(daily_profit > 0)
var winningDays2 = dailyProfit2.SelectValues(x => x > 0).Sum();
// draw_days = sum(daily_profit == 0)
var drawDays2 = dailyProfit2.SelectValues(x => x == 0).Sum();
// losing_days = sum(daily_profit < 0)
var losingDays2 = dailyProfit2.SelectValues(x => x < 0).Sum();
Console.ReadLine();
}
}
}

You can use a custom data type as a key in Deedle. If you want to be able to use resampling on the series, then this needs to support IComparable. You can either define your own type or use built-in Tuple.
Assuming we have some very basic data:
var ts =
new[] {
KeyValue.Create(new DateTime(2020,1,1), new { Value = 1.0, Kind = "A" }),
KeyValue.Create(new DateTime(2020,1,2), new { Value = 1.0, Kind = "A" }),
KeyValue.Create(new DateTime(2020,1,3), new { Value = 1.0, Kind = "B" }),
KeyValue.Create(new DateTime(2020,1,4), new { Value = 1.0, Kind = "B" }),
}.ToSeries();
The first thing we need to do is to change the key to be the date together with a kind. (In fact, you can get into trouble earlier in your code if you had duplicate dates!)
var byDateAndKind =
ts.SelectKeys(kvp => Tuple.Create(kvp.Key, kvp.Value.Value.Kind)).SortByKey();
Now the key is Tuple<DateTime, string> consisting of the date and the kind. You can now use ResampleEquivalence on this. Here, we use year and kind as the new key and sum values in group:
var aggByYearAndKind =
byDateAndKind.ResampleEquivalence(
(k) => Tuple.Create(k.Item1.Year, k.Item2),
(g) => g.Select(kvp => kvp.Value.Value).Sum());
aggByYearAndKind.Print();
This will print a series that maps 2020, "A" to 2 and also 2020, "B" to 2.
EDIT You are right - this does not seem to work. I was able to get it to work using GroupBy instead of ResampleEquvialence:
var dailyProfit2 =
ts.GroupBy(kvp =>
new { Date = new DateTime(kvp.Value.CloseDate.Year, kvp.Value.CloseDate.Month, kvp.Value.CloseDate.Day), Kind = kvp.Value.Pair })
.SelectValues(g => g.Select(kvp => kvp.Value.ProfitPercentage).Values.Sum());
// backtest_worst_day = min(daily_profit)
var worstDay2 = dailyProfit2.Min();
// backtest_best_day = max(daily_profit)
var bestDay2 = dailyProfit2.Max();
// winning_days = sum(daily_profit > 0)
var winningDays2 = dailyProfit2.Where(x => x.Value > 0).Values.Sum();
// draw_days = sum(daily_profit == 0)
var drawDays2 = dailyProfit2.Where(x => x.Value == 0).Values.Sum();
// losing_days = sum(daily_profit < 0)
var losingDays2 = dailyProfit2.Where(x => x.Value < 0).Values.Sum();

Map one class data to another class with iteration

I have a C# project and looking for simple solution for map one class object data to list of another class object.
This is my input class
public class RatesInput
{
public string Type1 { get; set; }
public string Break1 { get; set; }
public string Basic1 { get; set; }
public string Rate1 { get; set; }
public string Type2 { get; set; }
public string Break2 { get; set; }
public string Basic2 { get; set; }
public string Rate2 { get; set; }
public string Type3 { get; set; }
public string Break3 { get; set; }
public string Basic3 { get; set; }
public string Rate3 { get; set; }
}
This is my another class structure
public class RateDetail
{
public string RateType { get; set; }
public decimal Break { get; set; }
public decimal Basic { get; set; }
public decimal Rate { get; set; }
}
it has a object like below. (For easiering the understanding, I use hardcoded values and actually values assign from a csv file)
RatesInput objInput = new RatesInput();
objInput.Type1 = "T";
objInput.Break1 = 100;
objInput.Basic1 = 50;
objInput.Rate1 = 0.08;
objInput.Type2 = "T";
objInput.Break2 = 200;
objInput.Basic2 = 50;
objInput.Rate2 = 0.07;
objInput.Type3 = "T";
objInput.Break3 = 500;
objInput.Basic3 = 50;
objInput.Rate3 = 0.06;
Then I need to assign values to "RateDetail" list object like below.
List<RateDetail> lstDetails = new List<RateDetail>();
//START Looping using foreach or any looping mechanism
RateDetail obj = new RateDetail();
obj.RateType = //first iteration this should be assigned objInput.Type1, 2nd iteration objInput.Type2 etc....
obj.Break = //first iteration this should be assigned objInput.Break1 , 2nd iteration objInput.Break2 etc....
obj.Basic = //first iteration this should be assigned objInput.Basic1 , 2nd iteration objInput.Basic2 etc....
obj.Rate = //first iteration this should be assigned objInput.Rate1, 2nd iteration objInput.Rate2 etc....
lstDetails.Add(obj); //Add obj to the list
//END looping
Is there any way to convert "RatesInput" class data to "RateDetail" class like above method in C#? If yes, how to iterate data set?

Try this:
public class RatesList : IEnumerable<RateDetail>
{
public RatesList(IEnumerable<RatesInput> ratesInputList)
{
RatesInputList = ratesInputList;
}
private readonly IEnumerable<RatesInput> RatesInputList;
public IEnumerator<RateDetail> GetEnumerator()
{
foreach (var ratesInput in RatesInputList)
{
yield return new RateDetail
{
RateType = ratesInput.Type1,
Break = Convert.ToDecimal(ratesInput.Break1, new CultureInfo("en-US")),
Basic = Convert.ToDecimal(ratesInput.Basic1, new CultureInfo("en-US")),
Rate = Convert.ToDecimal(ratesInput.Rate1, new CultureInfo("en-US"))
};
yield return new RateDetail
{
RateType = ratesInput.Type2,
Break = Convert.ToDecimal(ratesInput.Break2),
Basic = Convert.ToDecimal(ratesInput.Basic2),
Rate = Convert.ToDecimal(ratesInput.Rate2, new CultureInfo("en-US"))
};
yield return new RateDetail
{
RateType = ratesInput.Type3,
Break = Convert.ToDecimal(ratesInput.Break3),
Basic = Convert.ToDecimal(ratesInput.Basic3),
Rate = Convert.ToDecimal(ratesInput.Rate3, new CultureInfo("en-US"))
};
}
}
IEnumerator IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
}
And use:
var list = new RatesList(new List<RatesInput>() { objInput });
foreach (var item in list)
{
Console.WriteLine(item.Basic);
}

You can use Reflection to get the properties info like this:
var props = objInput.GetType().GetProperties();
var types = props.Where(x => x.Name.StartsWith("Type"))
.Select(x => x.GetValue(objInput)).ToList();
var breaks = props.Where(x => x.Name.StartsWith("Break"))
.Select(x => x.GetValue(objInput)).ToList();
var basics = props.Where(x => x.Name.StartsWith("Basic"))
.Select(x => x.GetValue(objInput)).ToList();
var rates = props.Where(x => x.Name.StartsWith("Rate"))
.Select(x => x.GetValue(objInput)).ToList();
List<RateDetail> lstDetails = new List<RateDetail>();
for (int i = 0; i < types.Count; i++)
{
lstDetails.Add(new RateDetail
{
RateType = types[i].ToString(),
Break = Convert.ToDecimal(breaks[i]),
Basic = Convert.ToDecimal(basics[i]),
Rate = Convert.ToDecimal(rates[i])
});
}

Adding data from one list to another using linq

I need to populate a dropdown in my UI and hence added List object to the view model in my c# application. I am fetching the data in my controller code for the dropdown. What's the best way to assign data to the viewmodel object. Is linq an option?
I basically need to assign fundclasses to fundTrackRecord.FundClass
The main Viewmodel:
public class FundPerformanceVM
{
public FundPerformanceVM()
{
TrackRecord = new List<TrackRecordVM>();
}
public int FundId { get; set; }
public string FundName { get; set; }
public List<FundClassVM> FundClass { get; set; }
public string BenchmarkName1 { get; set; }
public string BenchmarkName2 { get; set; }
public List<TrackRecordVM> TrackRecord { get; set; }
public List<Tuple<string, string, string>> FundStatistics { get; set; }
}
public class FundClassVM
{
public int FundClassId { get; set; }
public string FundClass { get; set; }
}
Controller code:
var service = GetViewService<V_LEGAL_FUND_CLASS_SUMMARY>();
foreach (KeyValuePair<int, IEnumerable<FUND_PERFORMANCE>> entry in allPerformance)
{
var fundClasses = service.GetAll().Where(x => x.FUND_ID == entry.Key).Select(x => new { x.LEGAL_FUND_CLASS_ID, x.LEGAL_FUND_CLASS}).ToList();
var fundTrackRecord = new FundPerformanceVM();
fundTrackRecord.FundClass = ??;

If I understood correctly the structure of your model, you can try this:
fundTrackRecord.FundClass = fundClasses.Select(fc => new FundClassVM
{
FundClassId = fc.LEGAL_FUND_CLASS_ID,
FundClass = fc.LEGAL_FUND_CLASS
}).ToList();
You can also do this directly, replacing the code:
var fundClasses = service.GetAll().Where(x => x.FUND_ID == entry.Key).Select(x => new { x.LEGAL_FUND_CLASS_ID, x.LEGAL_FUND_CLASS}).ToList();
var fundTrackRecord = new FundPerformanceVM();
With:
var fundTrackRecord = new FundPerformanceVM();
fundTrackRecord.FundClass = service.GetAll().
Where(x => x.FUND_ID == entry.Key).
Select(fc => new FundClassVM
{
FundClassId = fc.LEGAL_FUND_CLASS_ID,
FundClass = fc.LEGAL_FUND_CLASS
}).ToList();

Unable to deserialize JSON array

Below is my class :
public class Employee : Base
{
public int Id { get; set; }
public string Fname { get; set; }
public DepartmentModel Department { get; set; }
}
public class DepartmentModel : Base
{
public int Id { get; set; }
public string DepartmentName { get; set; }
public List<Location> Locations { get; set; }
}
public class Locations
{
public string Area { get; set; }
public string StreetNo { get; set; }
public string Nearby { get; set; }
}
Response return from service:
var response = new
{
id = 100,
department = new
{
id = 200,
departmentName = "Abc",
locations = new[]
{
Employee.Department.Locations
.Select
(
lo => new
{
area = lo.Area,
streetNo = lo.streetNo,
nearby = lo.Nearby
}
).ToList()
}
}
};
return JsonConvert.SerializeObject(response);
Now when I try to deserialize this above JSON into my class Employee like below:
var deserialize = JsonConvert.DeserializeObject<Employee>(response.ToString());
Error:
How can I deserialize this above JSON?

The problem lies here:
locations = new[]
{
Employee.Department.Locations
.Select
(
lo => new
{
area = lo.Area,
streetNo = lo.streetNo,
nearby = lo.Nearby
}
).ToList()
}
The LINQ expression ends with .ToList() and thus is already returning a list of items. You are then wrapping that with new[] in an array. So, instead of being an array of Locations, the JSON is an array of an array of Locations.

Try removing the new[]. You don't want locations to be an array of lists
locations = Employee.Department.Locations
.Select(lo => new
{
area = lo.Area,
streetNo = lo.streetNo,
nearby = lo.Nearby
}
).ToList()

You need to instantiate a new Employee() and use the same casing as the classes:
var response = new Employee() // Instantiates Employee to ensure correct properties used.
{
Id = 100, // Has PascalCase.
Department = new DepartmentModel()
{
Id = 200,
DepartmentName = "Abc",
Locations = Employee.Department.Locations
.Select(lo => new Location
{
Area = lo.Area,
StreetNo = lo.StreetNo,
Nearby = lo.Nearby
}
).ToList()
}
};