We Keep Coding

Unable to get a distinct list that contains summed values

I have posted this earlier but the objective of what I am trying to achieve seems to have lost hence re-posting it to get explain myself better.
I have a collection that has duplicate productnames with different values. My aim is to get a list that would sum these productnames so that the list contains single record of these duplicates.
For e.g
If the list contains
Product A 100
Product A 200
The result object should contain
Product A 300
So as you can see in my code below, I am passing IEnumerable allocationsGrouped to the method. I am grouping by productname and summing the Emv fields and then looping it so that I created a new list of the type List and pass it to the caller method. The problem what I seeing here is on the following line of code Items = group. Items now contains original list without the sum. Hence the inner foreach loop runs more than ones because there are duplicates which defeats my purpose. I finally need to return result object that has non duplicate values which are summed based on the above criteria. Could you please tell me where I am going wrong.
private static List<FirmWideAllocationsViewModel> CreateHierarchy(string manStratName, IEnumerable<FIRMWIDE_MANAGER_ALLOCATION> allocationsGrouped, List<FirmWideAllocationsViewModel> result)
{
var a = allocationsGrouped
.Where(product => !string.IsNullOrEmpty(product.PRODUCT_NAME))
.GroupBy(product => product.PRODUCT_NAME)
.Select(group => new
{
ProductName = group.Key, // this is the value you grouped on - the ProductName
EmvSum = group.Sum(x => x.EMV),
Items = group
});
var b = a;
var item = new FirmWideAllocationsViewModel();
item.Hierarchy = new List<string>();
item.Hierarchy.Add(manStratName);
result.Add(item);
foreach (var ac in b)
{
var productName = ac.ProductName;
var emvSum = ac.EmvSum;
foreach (var elem in ac.Items)
{
var item2 = new FirmWideAllocationsViewModel();
item2.Hierarchy = new List<string>();
item2.Hierarchy.Add(manStratName);
item2.Hierarchy.Add(elem.PRODUCT_NAME);
item2.FirmID = elem.FIRM_ID;
item2.FirmName = elem.FIRM_NAME;
item2.ManagerStrategyID = elem.MANAGER_STRATEGY_ID;
item2.ManagerStrategyName = elem.MANAGER_STRATEGY_NAME;
item2.ManagerAccountClassID = elem.MANAGER_ACCOUNTING_CLASS_ID;
item2.ManagerAccountingClassName = elem.MANAGER_ACCOUNTING_CLASS_NAME;
item2.ManagerFundID = elem.MANAGER_FUND_ID;
item2.ManagerFundName = elem.MANAGER_FUND_NAME;
item2.Nav = elem.NAV;
item2.EvalDate = elem.EVAL_DATE.HasValue ? elem.EVAL_DATE.Value.ToString("MMM dd, yyyy") : string.Empty;
item2.ProductID = elem.PRODUCT_ID;
item2.ProductName = elem.PRODUCT_NAME;
item2.UsdEmv = Math.Round((decimal)elem.UsdEmv);
item2.GroupPercent = elem.GroupPercent;
item2.WeightWithEq = elem.WEIGHT_WITH_EQ;
result.Add(item2);
}
}
return result;
}

change it to:
var result = allocationsGrouped
.Where(product => !string.IsNullOrEmpty(product.PRODUCT_NAME))
.GroupBy(product => product.PRODUCT_NAME)
.Select(group => {
var product = group.First();
return new FirmWideAllocationsViewModel()
{
Hierarchy = new List<string>() { manStratName, product.PRODUCT_NAME },
FirmID = product.FIRM_ID,
FirmName = product.Item.FIRM_NAME,
ManagerStrategyID = product.MANAGER_STRATEGY_ID,
ManagerStrategyName = product.MANAGER_STRATEGY_NAME,
ManagerAccountClassID = product.MANAGER_ACCOUNTING_CLASS_ID,
ManagerAccountingClassName = product.MANAGER_ACCOUNTING_CLASS_NAME,
ManagerFundID = product.MANAGER_FUND_ID,
ManagerFundName = product.MANAGER_FUND_NAME,
Nav = product.NAV,
EvalDate = product.EVAL_DATE.HasValue ? product.EVAL_DATE.Value.ToString("MMM dd, yyyy") : string.Empty,
ProductID = product.PRODUCT_ID,
ProductName = product.PRODUCT_NAME,
UsdEmv = Math.Round((decimal)product.UsdEmv),
GroupPercent = product.GroupPercent,
WeightWithEq = product.WEIGHT_WITH_EQ,
//assign aggregate Sum here
EmvSum = group.Sum(x => x.EMV),
};
});

Is there any efficient way to optimize following Linq

private static List<Patient> GetPatientData()
{
return new List<Patient>()
{
new Patient(1,new List<Case>() { new Case(10, CaseType.ambulant)}),
new Patient(2,new List<Case>() { new Case(20, CaseType.ambulant), new Case(21, CaseType.ambulant), new Case(22, CaseType.stationaer),new Case(23, CaseType.teilstat) }),
new Patient(3,new List<Case>() { new Case(30, CaseType.ambulant), new Case(31, CaseType.ambulant), new Case(32, CaseType.stationaer), new Case(33, CaseType.stationaer), new Case(34, CaseType.teilstat) }),
new Patient(4,new List<Case>() { new Case(40, CaseType.ambulant), new Case(41, CaseType.stationaer), new Case(43, CaseType.teilstat), new Case(44, CaseType.ambulant), new Case(45, CaseType.stationaer), new Case(46, CaseType.teilstat) }),
new Patient(5,new List<Case>() {new Case(53, CaseType.teilstat),new Case(54, CaseType.teilstat) })
};
}
List<Patient> patientList = GetPatientData();
var result = patientList.SelectMany(item => item.CaseList.Select(itemCase=> itemCase.CaseType).Distinct());
foreach (CaseType item in result)
{
Console.WriteLine("CaseTypes = {0}",item);
}
The above code gives the list of Patient, from that I want a distinct case list. So is there any optimized way to do this from what I have done?
Dictionary<int, int> result = patientList.ToDictionary(item => item.PatientID , item=> item.CaseList.Select(x=>x.CaseType).Distinct().Count());
foreach (KeyValuePair<int,int> item in result)
{
Console.WriteLine("{0} {1}", item.Key,item.Value);
}
In Second case i am trying to get patientID & Distinct CaseType Count for that particular patient. can i optimize this one.

To get the distinct case types of all patients in that list, I used
var result =
(
from patient in patientList
from typ in patient.CaseList
select typ.CaseType
).Distinct();
foreach (var item in result)
{
Console.WriteLine("CaseTypes = {0}", item);
}
Of course, you could rewrite it method-style.
To get the same distinct case list, but per patient, try this:
var result =
(
from patient in patientList
group patient by patient.PatientID into g
from patient in g
from typ in patient.CaseList
select new { ID = g.Key, Type = typ.CaseType }
).Distinct();
foreach (var item in result)
{
Console.WriteLine("Patient {0} has the following case: {1}", item.ID, item.Type);
}
An alternative (less repeating) way to present the results is to group:
var result =
(
from patient in patientList
group patient by patient.PatientID into g
from p in g
select new { g.Key, List = p.CaseList.Select(c => c.CaseType).Distinct() }
).ToDictionary(kv => kv.Key, kv => kv.List);
foreach (var item in result)
{
Console.WriteLine("Patient {0} has the following cases:", item.Key);
foreach (var type in item.Value)
{
Console.WriteLine("\t{0}", type);
}
}

You are missing a last Distinct:
var result = patientList.SelectMany(item => item.CaseList.Select(itemCase => itemCase.CaseType).Distinct()).Distinct();
There's nothing to improve there.
You could choose to keep only the last Distinct (so there's one less Enumerator to be created) but having it gives you less results yielded out to your final Distinct. Performance then would change depending on the amount of data (number of Patients and Cases per Patient) though nothing that would make any difference.

How to break or Exit from Linq query

I need to find the 1st matching record between 2 generic Lists.
Below is the code I have written. But, even after a match is obtained, it is still processing further records. Is there any way to break from the below query? Something like "break" or "Exit for"
foreach (var itemOld in oldList)
{
var result = (from itemNew in newList
where itemNew.Id == itemOld.Id
select itemNew).ToList();
// Do processing
}

The keyword you are looking for is break;
foreach (var itemOld in oldList)
{
var result = (from itemNew in newList
where itemNew.Id == itemOld.Id
select itemNew).ToList();
if(someThingisTrue){
break;
}
}

You can do this. Both the inner and outer query will terminate as soon as a matching item is found:
foreach (var itemOld in oldList)
{
var result = (from itemNew in newList
where itemNew.Id == itemOld.Id
select itemNew).FirstOrDefault();
if (result != null)
{
// process result
break;
}
}
You can also combine them like this:
var result = (from itemNew in newList
from itemOld in oldList
where itemNew.Id == itemOld.Id
select itemNew).FirstOrDefault();
if (result != null)
{
// process result
}
The difference is that the first approach will go through newList repeatedly until a match is found. The second will go through oldList repeatedly until a match is found.
To address your comment below, if you want to process all the matches, just remove the break from the first example, or do this for the second version:
var results = from itemNew in newList
from itemOld in oldList
where itemNew.Id == itemOld.Id
select itemNew;
foreach (var item in results)
{
// process item
}

Just for fun.
var predicate = itemNew => oldList.FirstOrDefault(itemOld => itemOld.Id == itemNew.Id);
var result = newList.FirstOrDefault(predicate);
EDIT: as pointed out in the comments, I did stuff in the wrong order =(. Fixed for correctness.

A little bit late, but you can do it with a join:
using System;
using System.Collections.Generic;
using System.Linq;
public class Program
{
public class Item
{
public int Id { get; set; }
}
public static void Main()
{
var oldList = new List<Item>();
oldList.Add(new Item() { Id = 3 });
oldList.Add(new Item() { Id = 4 });
oldList.Add(new Item() { Id = 5 });
var newList = new List<Item>();
newList.Add(new Item() { Id = 1 });
newList.Add(new Item() { Id = 2 });
newList.Add(new Item() { Id = 3 });
// here is the linq join
var result =
newList.Join(
oldList,
item => item.Id,
item => item.Id,
(itemNew, itemOld) => itemNew).FirstOrDefault();
// outputs 3
Console.WriteLine(result.Id);
}
}

Save list to to database

I have created a function on my restaurant review site that finds the cuisine of the last review and then finds other reviews of the same cuisines with a greater average score and then saves the restaurant id of those reviews into a table on the database. However I keep on getting the error:
Cannot assign method group to an implicitly-typed local variable.
on the line restaurantid = choices.Any help would be grateful.
var averagescore = db.Reviews
.Where(r => r.Cuisine == review.Cuisine)
.Average(r => r.score);
var choices = (from r in db.Reviews
where r.score <= averagescore
select r.RestaurantId).ToList;
foreach (var item in choices)
{
var suggestion = new Suggestion()
{
id = review.id,
Userid = review.UserId,
restaurantid = choices
};
db.Suggestions.Add(suggestion);
db.SaveChanges();
}

Following line:
var choices = (from ...).ToList;
Should be:
var choices = (from ...).ToList();
Secondly, it looks to me that restaurantid is of type int. With your code you're assigning a List<int> to the int. This should be item, from the loop.

You need to make the following change:
var averagescore = db.Reviews
.Where(r => r.Cuisine == review.Cuisine)
.Average(r => r.score);
var choices = (from r in db.Reviews
where r.score <= averagescore
select r.RestaurantId).ToList;
foreach (var item in choices)
{
var suggestion = new Suggestion()
{
id = review.id,
Userid = review.UserId,
restaurantid = item //here was your problem, you need to assign an id not a list of ids
};
db.Suggestions.Add(suggestion);
db.SaveChanges();
}

Have you tried like this:
var choices = (from r in db.Reviews
where r.score <= averagescore
select r).ToList;
foreach (var item in choices)
{
var suggestion = new Suggestion()
{
id = item.id,
Userid = item.UserId,
restaurantid = item.Restaurantid
};
db.Suggestions.Add(suggestion);
db.SaveChanges();
}

query to get all action during for each hour

i want to run and print a query that shows the number of orders per each hour in a day(24).
should look like:
hour-1:00, number of orders-5
hour-2:00, number of orders-45
hour-3:00, number of orders-25
hour-4:00, number of orders-3
hour-5:00, number of orders-43
and so on...
i try:
public void ShowBestHours()
{
using (NorthwindDataContext db = new NorthwindDataContext())
{
var query =
from z in db.Orders
select new Stime
{
HourTime = db.Orders.GroupBy(x => x.OrderDate.Value.Hour).Count(),
};
foreach (var item in query)
{
Console.WriteLine("Hour : {0},Order(s) Number : {1}", item.HourTime, item.Count);
}
}
}
public class Stime
{
public int HourTime { get; set; }
public int Count { get; set; }
}

You need to change your query to
var query =
from z in db.Orders
group z by z.OrderDate.Value.Hour into g
select new Stime{ HourTime = g.Key, Count=g.Count () };
or alternatively
var query = db,Orders.GroupBy (o => o.OrderDate.Value.Hour).Select (
g => new Stime{ HourTime=g.Key, Count=g.Count () });
In my copy of Northwind all of the OrderDate values are dates only so the result is just
HourTime = 0, Count = 830.
I'm assuming you're just experimenting with grouping. Try grouping by day of week like this
var query = db.Orders.GroupBy (o => o.OrderDate.Value.DayOfWeek).Select (
g => new { DayOfWeek=g.Key, Count=g.Count () });
which gives a more useful result.

You aren't setting Stime.Count anywhere in your query and you aren't grouping by hour correctly. I haven't seen your exact setup of course, but I think the following should work for you.
var query =
from z in db.Orders
group z by z.OrderDate.Value.Hour into g
select new Stime() { HourTime = g.Key, Count = g.Count() };
foreach (var item in query)
{
Console.WriteLine("Hour : {0},Order(s) Number : {1}", item.HourTime, item.Count);
}

Try this:
public void ShowBestHours()
{
using (NorthwindDataContext db = new NorthwindDataContext())
{
var query = db.Orders.GroupBy(x => x.OrderDate.Value.Hour).OrderByDescending(x => x.Count()).Select(x => new Stime { HourTime = x.Key, Count = x.Count() });
foreach (var item in query)
{
Console.WriteLine("Hour : {0},Order(s) Number : {1}", item.HourTime, item.Count);
}
}
}