Suffering sadly from brain fade. I have the following scenario:
void Main()
{
List<CaseBase> caseList = new List<UserQuery.CaseBase>();
caseList.Add(new CaseBase() {CaseID = 1, CaseSequence = 1, CaseStatus = 1});
caseList.Add(new CaseBase() {CaseID = 1, CaseSequence = 2, CaseStatus = 2});
caseList.Add(new CaseBase() {CaseID = 2, CaseSequence = 1, CaseStatus = 1});
var cases = caseList.Where(x => new List<int> {2}.Contains(x.CaseStatus));
}
// Define other methods and classes here
public class CaseBase
{
public int CaseID {get;set;}
public int CaseSequence {get;set;}
public int CaseStatus {get;set;}
}
Which returns the expected
CaseID
CaseSequence
CaseStatus
1
2
2
What I want are all cases with the same ID where one of them has a status of 2.
CaseID
CaseSequence
CaseStatus
1
1
1
1
2
2
Which should be simple but I'm struggling for a simple solution.
There are a couple of ways to proceed:
You can combine the cases by CaseID and select the matching groups and then break them apart:
var cases = caseList
.GroupBy(c => c.CaseID)
.Where(cg => cg.Any(c => new List<int> { 2 }.Contains(c.CaseStatus)))
.SelectMany(cg => cg);
You can find the desired CaseIDs and then get all matching cases:
var wantedCaseIDs = caseList
.Where(c => new List<int> { 2 }.Contains(c.CaseStatus))
.Select(c => c.CaseID)
.ToHashSet();
var cases = caseList.Where(c => wantedCaseIDs.Contains(c.CaseID));
Or you might want to do it like this:
void Main()
{
List<CaseBase> caseList = new List<UserQuery.CaseBase>();
caseList.Add(new CaseBase() { CaseID = 1, CaseSequence = 1, CaseStatus = 1 });
caseList.Add(new CaseBase() { CaseID = 1, CaseSequence = 2, CaseStatus = 2 });
caseList.Add(new CaseBase() { CaseID = 2, CaseSequence = 1, CaseStatus = 1 });
var cases = caseList.Where(x => new List<int> { 2 }.Contains(x.CaseStatus))
.Join(caseList,x => x.CaseID,y => y.CaseID,(x,y) => new {x,y})
.Select(z => z.y)
.Dump();
}
Related
Please consider this list:
List<Data> lst = new List<Data>
{
new Data() { Id = 1, Val1 = 100 },
new Data() { Id = 1, Val1 = 200 },
new Data() { Id = 1, Val1 = 300 },
new Data() { Id = 2, Val1 = 100 },
new Data() { Id = 2, Val1 = 200 },
new Data() { Id = 3, Val1 = 300 },
new Data() { Id = 3, Val1 = 300 },
new Data() { Id = 3, Val1 = 300 },
new Data() { Id = 1, Val1 = 200 },
new Data() { Id = 1, Val1 = 200 },
new Data() { Id = 1, Val1 = 200 },
new Data() { Id = 2, Val1 = 200 },
new Data() { Id = 3, Val1 = 100 },
new Data() { Id = 3, Val1 = 100 },
};
and then this code:
decimal Cumulative_Probability = 0;
var Result1 = (lst.OrderBy(o => o.Id).GroupBy(x => new { x.Val1 })
.Select(y => new
{
y.Key.Val1,
Probability = (Convert.ToDecimal(y.Count()) / lst.Count),
Cumulative_Probability = (Cumulative_Probability =
Cumulative_Probability +
(Convert.ToDecimal(y.Count()) / lst.Count))
})).OrderBy(o => o.Val1).ToList();
this code works fine and Cumulative_Probability calculated correctly.
Now please consider this code:
decimal Cumulative_Probability2 = 0;
var Result2 = (lst.OrderBy(o => o.Id).GroupBy(x => new { x.Id, x.Val1 })
.Select(y => new
{
y.Key.Id,
y.Key.Val1,
Probability = (Convert.ToDecimal(y.Count())
/ lst.Where(o => o.Id == y.Key.Id).Count()),
Cumulative_Probability = (Cumulative_Probability2 =
Cumulative_Probability2 +
(Convert.ToDecimal(y.Count()) /
lst.Where(o => o.Id == y.Key.Id).Count()))
})).OrderBy(o => o.Id).ThenBy(o => o.Val1).ToList();
this code generate this result:
As you can see Probability calculated in each group correctly, but not Cumulative_Probability. I want to calculate Cumulative_Probability in each Id group (group records first accourding Id then Val1) and Cumulative_Probability2 doesn't reset in each group. How I can calculate Cumulative_Probability in each group?
Thanks
Edit 1)
I want this result:
Id Val1 Probability Cumulative_Probability
-------------------------------------------------------------------------
1 100 0.16 0.16
1 200 0.66 0.82
1 300 0.16 0.98
2 100 0.33 0.33
2 200 0.66 0.66
...
I managed to do this with the help of an extension method which accumulates the cumulative probability, along with some nested GroupBy. I'm sure there must be an easier way, but I'm scratching my head trying to find it.
The extension is:
public static class EnumerableExtensions
{
public static IEnumerable<TResult> Accumulate<TSource, TAccumulate, TResult>(
this IEnumerable<TSource> source,
TAccumulate seed,
Func<TAccumulate, TSource, (TAccumulate,TResult)> accumulator)
{
var acc = seed;
foreach(TSource value in source)
{
var (newSeed, newSource) = accumulator.Invoke(acc, value);
yield return newSource;
acc = newSeed;
}
}
}
And the finished code looks like:
var result = lst.GroupBy( x => x.Id)
.SelectMany( (grpId,i) => grpId.GroupBy(x => x.Val1)
.Accumulate(0M, (acc,grpVal) => (acc + (decimal)grpVal.Count()/grpId.Count(), new {
Id = grpId.Key,
Val1 = grpVal.Key,
Probability = (decimal)grpVal.Count()/grpId.Count(),
Cumulative_Probability = acc + ((decimal)grpVal.Count()/grpId.Count())
}))
)
.OrderBy(x => x.Id);
Live example: https://dotnetfiddle.net/dvW1qo
This code works:
var Result2 = (from a in lst.OrderBy(o => o.Id)
group a by new { a.Id, a.Val1 } into grp
select new
{
grp.Key.Id,
grp.Key.Val1,
Probability = (Convert.ToDecimal(grp.Count()) / lst.Where(o => o.Id == grp.Key.Id).Count()),
Cumulative_Probability = (from b in lst.Where(o => o.Id == grp.Key.Id && o.Val1 <= grp.Key.Val1)
group b by new { b.Val1 } into grp2
select new
{
Probability2 = (Convert.ToDecimal(grp2.Count()) / lst.Where(o => o.Id == grp.Key.Id).Count())
}).Sum(o => o.Probability2)
}).OrderBy(o => o.Id).ThenBy(o => o.Val1).ToList();
I have two lists:
var qtys = new List<InventoryQuantity>()
{
new InventoryQuantity() { WarehouseId = 1, QuantityInWarehouse = 0 },
new InventoryQuantity() { WarehouseId = 2, QuantityInWarehouse = 452 },
new InventoryQuantity() { WarehouseId = 3, QuantityInWarehouse = 184 },
new InventoryQuantity() { WarehouseId = 4, QuantityInWarehouse = 328 },
new InventoryQuantity() { WarehouseId = 5, QuantityInWarehouse = 0 },
};
var times = new List<WarehouseTransitTime>()
{
new WarehouseTransitTime() { WarehouseId = 1, TransitDays = 1 },
new WarehouseTransitTime() { WarehouseId = 2, TransitDays = 4 },
new WarehouseTransitTime() { WarehouseId = 3, TransitDays = 2 },
new WarehouseTransitTime() { WarehouseId = 4, TransitDays = 3 },
new WarehouseTransitTime() { WarehouseId = 5, TransitDays = 5 },
};
class InventoryQuantity
{
public int WarehouseId { get; set; }
public int QuantityInWarehouse { get; set; }
}
class WarehouseTransitTime
{
public int WarehouseId { get; set; }
public int TransitDays { get; set; }
}
I need to return the WarehouseId from qtys where the Quantity > 0 and the WarehouseId equals the minimum transit days WarehouseId in times.
I know I can do something like below but seems clunky and there must be an elegant solution.
public int NearestWarehouse()
{
var withQty = qtys.Where(i => i.QuantityInWarehouse > 0);
var orderedTransit = times.OrderBy(tt => tt.TransitDays).ToList();
//loop and compare
}
Example data:
qtys
WarehouseId | Quantity
1 | 0
2 | 452
3 | 184
4 | 328
5 | 0
times
WarehouseId | TransitTime
1 | 1
2 | 4
3 | 2
4 | 3
5 | 5
Expected output would be 3, because warehouse 3 has inventory and the shortest transit time (2)
It seems to me that the cleanest and simplest query is this:
var query =
from q in qtys
where q.QuantityInWarehouse > 0
join t in times on q.WarehouseId equals t.WarehouseId
orderby t.TransitDays
select q.WarehouseId;
var warehouseId = query.FirstOrDefault();
This gives me 3.
What you want is a group join:
Functional Syntax
var query1 = qtys.Where(q => q.QuantityInWarehouse > 0)
.GroupJoin(times, q => q.WarehouseId, t => t.WarehouseId, (q, t) => new { q.WarehouseId, TransitDays = t.DefaultIfEmpty().Min(grp => grp?.TransitDays) })
.OrderBy(g => g.TransitDays)
.FirstOrDefault();
Query Syntax
var query2 = from q in qtys
join t in times on q.WarehouseId equals t.WarehouseId into grp
where q.QuantityInWarehouse > 0
select new
{
q.WarehouseId,
TransitDays = grp.DefaultIfEmpty().Min(g => g?.TransitDays)
};
var result = query2.OrderBy(g => g.TransitDays)
.FirstOrDefault();
A group join will join two lists together on their corresponding keys--similar to a database join--and the associated values to those keys will be grouped into an enumerable. From that enumerable, you can derive the minimum value that you care about, TransitDays in this case.
There is no equivalent to "first or default" in query syntax. The easiest approach is just to apply the same OrderBy and FirstOrDefault against the query variable, as demonstrated above.
Well you mention an AND relation between the two, right?
I was thinking of databases with a forignkey... but Linq prety much does it if your lists aren't to big:
keys = qtys.Where(i => i.QuantityInWarehouse > 0).Select(i => i.WarehouseId).ToList();
// get the smallest not a list
var result = times.Where(tt => keys.Contains(tt.wharehouseId)).orderby(tt => tt.Transitdays).FirstOrDefault();
Otherwise you could have Dictionary with ID as key...
You can do it like this..
var withQty = (from q in qtys
join t in times on q.WarehouseId equals t.WarehouseId
where q.QuantityInWarehouse > 0
select new { q.WarehouseId, t.TransitDays })
.OrderBy(item => item.TransitDays).FirstOrDefault();
return withQty?.WarehouseId ?? 0;
I have array:
OrderProduct[] OrderProductsOrder = new OrderProduct[] {
new OrderProduct { OrderID = 1, ProductID = 2, OrderCustomerID = 1 },
new OrderProduct { OrderID = 2, ProductID = 1, OrderCustomerID = 1 },
new OrderProduct { OrderID = 1, ProductID = 3, OrderCustomerID = 1 },
new OrderProduct { OrderID = 2, ProductID = 1, OrderCustomerID = 2 },
new OrderProduct { OrderID = 1, ProductID = 2, OrderCustomerID = 3 },
new OrderProduct { OrderID = 2, ProductID = 1, OrderCustomerID = 3 }};
How to split this array to three arrays, order by CustomerID, using linq.
Result should be this three arrays:
OrderProduct[] Customer1Order = new OrderProduct[] {
new OrderProduct { OrderID = 1, ProductID = 2, OrderCustomerID = 1 },
new OrderProduct { OrderID = 2, ProductID = 1, OrderCustomerID = 1 },
new OrderProduct { OrderID = 1, ProductID = 3, OrderCustomerID = 1 }};
OrderProduct[] Customer2Order = new OrderProduct[]
{new OrderProduct { OrderID = 2, ProductID = 1, OrderCustomerID = 2 }};
OrderProduct[] Customer3Order = new OrderProduct[] {
new OrderProduct { OrderID = 1, ProductID = 2, OrderCustomerID = 3 },
new OrderProduct { OrderID = 2, ProductID = 1, OrderCustomerID = 3 }};
Edited, removed the GroupBy() suggestion as it was redundant (courtesy of Innat3)
No reason to use GroupBy() at all, just use Where.
OrderProduct[] Customer1Order = OrderProductsOrder.Where(o => o.OrderCustomerID == 1).ToArray();
OrderProduct[] Customer2Order = OrderProductsOrder.Where(o => o.OrderCustomerID == 2).ToArray();
OrderProduct[] Customer3Order = OrderProductsOrder.Where(o => o.OrderCustomerID == 3).ToArray();
Start by grouping the entries by OrderCustomerID, and constructing an array from each group. After that, add groups to a dictionary:
var byCustId = OrderProductsOrder
.GroupBy(p => p.OrderCustomerID)
.ToDictionary(g => g.Key, g => g.ToArray());
Now you can grab individual arrays with TryGetValue or operator []:
OrderProduct[] customer2Order;
if (byCustId.TryGetValue(2, out customer2Order) {
... // Use customer2Order array
}
I have a list to search a table,
List<long> searchListIds = new List<long>();
searchListIds.Add(1);
searchListIds.Add(2);
List<long> searchListFieldValues = new List<long>();
searchListFieldValues.Add(100);
searchListFieldValues.Add(50);
and my query is:
var adsWithRelevantadFields =
from adField in cwContext.tblAdFields
group adField by adField.adId into adAdFields
where searchListIds.All(i => adAdFields.Select(co => co.listId).Contains(i))
&& searchListFieldValues.All(i => adAdFields.Select(co => co.listFieldValue).Contains(i))
select adAdFields.Key;
everything is ok, but now: i need to get all records that meet less than searchListFieldValues. i mean:
all adId that have (listId == 1)&(listFieldValue <100) AND (listId == 2)&(listFieldValue <50)
contains part must change to something like contains-less
example:
cwContext.tblAdFields:
id 1 2 3 4 5 6 7
adId 1 2 1 2 3 3 3
listId 1 1 2 2 1 2 3
listfieldValue 100 100 50 50 100 49 10
Now if I want to get (listId == 1)&(listFieldValue ==100) AND (listId == 2)&(listFieldValue ==50) my code works, and return id adId: 1,2
but I can't get
all adId that have (listId == 1)&(listFieldValue ==100) AND (listId == 2)&(listFieldValue <50)
it must return 3
You should try changing Contains to Any, but I'm not sure if LINQ to Entities will translate it correctly into proper SQL statement.
var adsWithRelevantadFields =
from adField in cwContext.tblAdFields
group adField by adField.adId into adAdFields
where searchListIds.All(i => adAdFields.Select(co => co.listId).Contains(i))
&& searchListFieldValues.All(i => adAdFields.Select(co => co.listFieldValue).Any(x => x < i))
select adAdFields.Key;
Here is a full example that should work if I understood you correctly:
class Program
{
static void Main(string[] args)
{
List<int> searchListIds = new List<int>
{
1,
2,
};
List<int> searchListFieldValues = new List<int>
{
100,
50,
};
List<Tuple<int, int>> searchParameters = new List<Tuple<int,int>>();
for (int i = 0; i < searchListIds.Count; i++)
{
searchParameters.Add(new Tuple<int,int>(searchListIds[i], searchListFieldValues[i]));
}
List<AdField> adFields = new List<AdField>
{
new AdField(1, 1, 1, 100),
new AdField(2, 2, 1, 100),
new AdField(3, 1, 2, 50),
new AdField(4, 2, 2, 50),
new AdField(5, 3, 1, 100),
new AdField(6, 3, 2, 49),
new AdField(7, 3, 3, 10)
};
var result = adFields.Where(af => searchParameters.Any(sp => af.ListId == sp.Item1 && af.ListFieldValue < sp.Item2)).Select(af => af.AdId).Distinct();
foreach (var item in result)
{
Console.WriteLine(item);
}
Console.Read();
}
public class AdField
{
public int Id { get; private set; }
public int AdId { get; private set; }
public int ListId { get; private set; }
public int ListFieldValue { get; private set; }
public AdField(int id, int adId, int listId, int listFieldValue)
{
Id = id;
AdId = adId;
ListId = listId;
ListFieldValue = listFieldValue;
}
}
}
First, you're probably looking for functionality of Any() instead of Contains(). Another thing is that if your search criteria consists of two items - use one list of Tuple<int,int> instead of two lists. In this case you will e able to efficiently search by combination of listId and fieldValue:
var result = from adField in cwContext.tblAdFields
where searchParams.Any(sp => adField.listId == sp.Item1 && adField.listFieldValue < sp.Item2)
group adField by adField.adId into adAdFields
select adAdField.Key;
Have a list with deviceIds and corresponding actions to be taken on device.
var results= new List<Result>
{
new Result{ DeviceId= 1, ActionType = 1 },
new Result{ DeviceId= 1, ActionType = 2 },
new Result{ DeviceId= 1, ActionType = 3 },
new Result{ DeviceId= 2, ActionType = 1 },
new Result{ DeviceId= 3, ActionType = 1 },
new Result{ DeviceId= 4, ActionType = 1 },
new Result{ DeviceId= 5, ActionType = 1 },
new Result{ DeviceId= 6, ActionType = 1 },
new Result{ DeviceId= 6, ActionType = 2 },
};
How do I filter deviceIds unique in the list(no DeviceId 1), and assign it back to var "results"
results = List<Result>
{
new Result{ DeviceId= 2, ActionType = 1 },
new Result{ DeviceId= 3, ActionType = 1 },
new Result{ DeviceId= 4, ActionType = 1 },
new Result{ DeviceId= 5, ActionType = 1 },
};
Have tried using groupby and couldn't move forward
results = from result in results
group result by result.DeviceId
into groupedResultsByDevice
where groupedResultsByDevice.Count() == 1
select ????
Besides answer with query syntax, in method syntax LINQ query it will be:
results = results.GroupBy(r => r.DeviceId)
.Where(g => g.Key != 1 && g.Count() == 1)
.Select(g => g.First())
.ToList();
After grouping you can select the first (and only element of the group):
results = from result in results
group result by result.DeviceId
into groupedResultsByDevice
where groupedResultsByDevice.Count() == 1
select groupedResultsByDevice.First(); // <---
results = from r in results
group r by r.DeviceId into g
where g.Count() == 1
select g.First()
You can make it a little bit more efficient replacing g.Count() with !g.Skip(1).Any():
results = from r in results
group r by r.DeviceId into g
where !g.Skip(1).Any()
select g.First()
It will return false as soon as second element is found, instead of counting all items in the group.
Check this out
public static void Main()
{
var results = new List<Result>
{
new Result {DeviceId = 1, ActionType = 1},
new Result {DeviceId = 1, ActionType = 2},
new Result {DeviceId = 1, ActionType = 3},
new Result {DeviceId = 2, ActionType = 1},
new Result {DeviceId = 3, ActionType = 1},
new Result {DeviceId = 4, ActionType = 1},
new Result {DeviceId = 5, ActionType = 1},
new Result {DeviceId = 6, ActionType = 1},
new Result {DeviceId = 6, ActionType = 2},
};
List<Result> result = results
.GroupBy(x => x.DeviceId)
.Where(x => x.Count() == 1)
.SelectMany(x => x)
.Distinct()
.ToList();
result.ForEach(Console.WriteLine);
Console.ReadLine();
}
public sealed class Result : IEqualityComparer<Result>
{
public int DeviceId { get; set; }
public int ActionType { get; set; }
public bool Equals(Result x, Result y)
{
if (ReferenceEquals(x, y)) return true;
if (ReferenceEquals(x, null)) return false;
if (ReferenceEquals(y, null)) return false;
if (x.GetType() != y.GetType()) return false;
return x.DeviceId == y.DeviceId && x.ActionType == y.ActionType;
}
public int GetHashCode(Result obj)
{
unchecked
{
return (obj.DeviceId*397) ^ obj.ActionType;
}
}
public override string ToString()
{
return string.Format("DeviceId: {0}, ActionType: {1}", DeviceId, ActionType);
}
}
Result output:
DeviceId: 2, ActionType: 1
DeviceId: 3, ActionType: 1
DeviceId: 4, ActionType: 1
DeviceId: 5, ActionType: 1