SQL to Linq then to Lambda using navigation properties - c#

I'm trying to build a lambda expression to get the grand total but I'm still struggling to achieve the desired result. I've managed to achieve the same using SQL and LINQ using joints but it would be great if someone could give me a hand to re-write the query using lambda and navigation properties (without joints).
SQL Query:
SELECT SUM(a.[Quantity] * (a.[Price] + b.[ExtraValue])) + SUM(d.SubMealTotal * a.[Quantity]) AS [Total]
FROM [dbo].[OrderedMeals] a
INNER JOIN [dbo].[OrderedMealPortions] b
ON a.Id = b.[OrderedMealId]
LEFT OUTER JOIN (SELECT OrderedMealId, Sum(Price) AS SubMealTotal FROM [dbo].[OrderedSubMeals]
GROUP BY OrderedMealId) AS d
ON a.Id = d.[OrderedMealId]
WHERE a.[Quantity] > 0
Then the LINQ - Please let me know if I'm missing something here or there is a better way:
(from orderedMeal in _context.OrderedMeals.Where(x => x.Quantity > 0)
join orderedMealPortion in _context.OrderedMealPortions
on orderedMeal.Id equals orderedMealPortion.OrderedMealId
join orderedSubMeal in _context.OrderedSubMeals
on orderedMeal.Id equals orderedSubMeal.OrderedMealId into gs
from subOrderedSubMeal in gs.DefaultIfEmpty()
group subOrderedSubMeal by new { subOrderedSubMeal.OrderedMealId, orderedMeal.Price, orderedMeal.Quantity, orderedMealPortion.ExtraValue } into g
select new
{
MealTotal = (g.Key.ExtraValue + g.Key.Price) * g.Key.Quantity + g.Sum(x => x.Price * g.Key.Quantity),
}).Sum(x => x.MealTotal); // Not sure how to get the sum using LINQ
Entities:
public class OrderedMeal
{
public int Id { get; set; }
public int Quantity { get; set; }
public decimal Price { get; set; }
public int OrderedMealPortionId { get; set; }
public OrderedMealPortion? OrderedMealPortion { get; set; }
public ICollection<OrderedSubMeal>? OrderedSubMeals { get; set; }
}
public class OrderedMealPortion
{
public int Id { get; set; }
public int OrderedMealId { get; set; }
public OrderedMeal? OrderedMeal { get; set; }
public decimal? ExtraValue { get; set; }
}
public class OrderedSubMeal
{
public int Id { get; set; }
public int OrderedMealId { get; set; }
public OrderedMeal? OrderedMeal { get; set; }
public decimal Price { get; set; }
}

I can't test with a database, but I think this implements the query logic and will produce the same result:
var ans = OrderedMeals
.Where(om => om.Quantity > 0 && om.OrderedMealPortion != null)
.Sum(om => om.Quantity * (om.Price +
om.OrderedMealPortion!.ExtraValue +
(om.OrderedSubMeals != null ? om.OrderedSubMeals.Sum(osm => osm.Price) : 0)) );

This is direct translation from the SQL:
var groupingQuery =
from sm in _context.OrderedSubMeals
group sm by new { sm.OrderedMealId } into g
select new
{
g.Key.OrderedMealId,
SubMealTotal = g.Sum(x => x.Price)
};
var query =
from om in _context.OrderedMeals
join g in groupingQuery on om.Id equals g.OrderedMealId into gj
from g in gj.DefaultIfEmpty()
where om.Quantity > 0
select new { om, om.OrderedMealPortion, g };
var result = query.Sum(x => x.om.Quantity * (x.om.Price + x.OrderedMealPortion.ExtraValue + x.g.SubMealTotal));
But I have feeling that query can be simplified without grouping.

Related

How to Get Last Record Using LINQ - Entity Framework in SQLite

I need to translate the following SQLite query to LINQ in C#
SELECT sup.SupplierName, sup.SupplierID, pr.Price, max(pr.AddedDate)
FROM Suppliers sup
LEFT JOIN ItemsPrices pr
USING(SupplierID)
WHERE pr.ItemID = '22'
GROUP BY sup.SupplierName
I've searched about all web site and tried the following LINQ query and it does group like what I want but doesn't select latest date. I'm newbie in LINQ please help me
internal List<LatestPriceDbo> GetLatestPrice(int _itemid)
{
using (dbContext context = new dbContext())
{
var groupedPrice = from a in context.ItemsPrices
where a.ItemId == _itemid
orderby a.Id descending
group a by new { a.ItemId, a.SupplierId } into g
select new ItemsPrice
{
SupplierId = g.Key.SupplierId,
ItemId = g.Key.ItemId,
Price = g.FirstOrDefault().Price,
AddedDate = g.Max(s => s.AddedDate)
};
var result = (from c in context.Suppliers
from k in groupedPrice
where k.ItemId == _itemid && c.SupplierId == k.SupplierId
select new LatestPriceDbo
{
supid = c.SupplierId,
supname = c.SupplierName,
price = k.Price,
addeddate = k.AddedDate
}).ToList();
return result;
}
}
internal class LatestPriceDbo
{
public int supid { get; set; }
public string supname { get; set; }
public decimal price { get; set; }
public string addeddate { get; set; }
}
I am using Database-First.
You should be able to use a LINQ Join I have mocked up something which might point you in the correct direction:
Notes
use the join first to get the set you looking for
you can then do a nested select for the max based on supplierId.
from a in context.ItemsPrices
join s in context.Suppliers on a.SupplierId equals s.supplierId
where a.ItemId == _itemid
orderby a.Id descending
select new ItemsPrice
{
SupplierName = s.SupplierName
SupplierId = a.SupplierId,
ItemId = a.ItemId,
Price = a.FirstOrDefault().Price,
AddedDate = context.ItemsPrices.Where(x => x.SupplierId == a.SupplierId).Max(s => s.AddedDate)
};
I solved the problem owing to Kevin's suggestion. I did need to be more search on web to improve the code block of Kevin's comment and I did.
internal List<LatestPriceDbo> GetLatestPrice(int _itemid)
{
using (dbContext context = new dbContext())
{
var result = (from a in context.ItemsPrices
join s in context.Suppliers on a.SupplierId equals s.SupplierId
where a.ItemId == _itemid
orderby a.Id descending
group new { a, s } by new { a.SupplierId, a.ItemId } into grb
select new LatestPriceDbo
{
supname = grb.FirstOrDefault().s.SupplierName,
supid = grb.Key.SupplierId,
itemid = grb.Key.ItemId,
price = context.ItemsPrices
.Where(x => x.ItemId == grb.FirstOrDefault().a.ItemId)
.OrderByDescending(z => z.Id).Select(z => z.Price)
.FirstOrDefault(),
addeddate = context.ItemsPrices
.Where(x => x.SupplierId == grb.FirstOrDefault().a.SupplierId)
.Max(s => s.AddedDate)
}).ToList();
return result;
}
}
internal class LatestPriceDbo
{
public int itemid { get; set; }
public int supid { get; set; }
public string supname { get; set; }
public decimal price { get; set; }
public string addeddate { get; set; }
public int recordid { get; set; }
}

SQL to LINQ with multiple joins and group by

I am working to convert the below SQL code to LINQ query for MVC. It got multiple nested joins and group by.
SELECT UnitTracts.Id,
UnitTracts.UnitId,
Leases.Id,
Leases.Lessor,
Leases.Lessee,
Leases.Alias,
Leases.LeaseDate,
Leases.GrossAcres,
IIf([Page] Is Null,[VolumeDocumentNumber],[VolumeDocumentNumber] + '/' + [Page]) AS [Vol/Pg],
Leases.Legal,
Interests.TractId,
Leases.NetAcres,
UnitTracts.AcInUnit
FROM (UnitTracts INNER JOIN (((WorkingInterestGroups INNER JOIN Interests ON WorkingInterestGroups.Id = Interests.WorkingInterestGroupId)
INNER JOIN Tracts ON Interests.TractId = Tracts.Id)
INNER JOIN Leases ON WorkingInterestGroups.LeaseId = Leases.Id)
ON UnitTracts.TractId = Tracts.Id)
LEFT JOIN AdditionalLeaseInfo ON Leases.Id = AdditionalLeaseInfo.LeaseId
where unitId = 21
GROUP BY UnitTracts.Id,
UnitTracts.UnitId,
Leases.Id,
Leases.Lessor,
Leases.Lessee,
Leases.Alias,
Leases.LeaseDate,
Leases.GrossAcres,
IIf([Page] Is Null,[VolumeDocumentNumber],[VolumeDocumentNumber] + '/' + [Page]),
Leases.Legal,
Interests.TractId,
Leases.NetAcres,
UnitTracts.AcInUnit
This the query I got but it returns less records. I tried to convert from SQL to LINQ but it did not work. I really stuck now.
var leases = (from l in db.Leases
where l.Active
join ali in db.AdditionalLeaseInfoes on l.Id equals ali.LeaseId
where ali.Active
join wig in db.WorkingInterestGroups on l.Id equals wig.LeaseId
where wig.Active
join interest in db.Interests on wig.Id equals interest.WorkingInterestGroupId
where interest.Active
join tr in db.Tracts on interest.TractId equals tr.Id
where tr.Active
join ut in db.UnitTracts on tr.Id equals ut.TractId
where ut.Active
group new { l, wig, interest, tr, ali, ut } by
new
{
Id = ut.Id,
UnitId = ut.UnitId,
LeaseId = l.Id,
Lessor = l.Lessor,
Lessee = l.Lessee,
Alias = l.Alias,
LeaseDate = l.LeaseDate,
GrossAcres = l.GrossAcres,
VolPg = l.Page == null ? l.VolumeDocumentNumber : l.VolumeDocumentNumber + "/" + l.Page,
Legal = l.Legal,
TractId = interest.TractId,
NetAcres = l.NetAcres,
AcInUnit = ut.AcInUnit
} into lease
select new LeasesViewModel
{
UnitId = lease.Key.UnitId,
TractId = lease.Key.TractId,
LeaseId = lease.Key.LeaseId,
LeaseAlias = lease.Key.Alias,
Pooling = lease.Where(x => x.l.Id == lease.Key.LeaseId).Select(x => x.l.NoPooling).FirstOrDefault() ? "No" :
lease.Where(x => x.l.Id == lease.Key.LeaseId).Select(x => x.l.Pooling).FirstOrDefault() ? "Yes" : "No Review",
Lessor = lease.Key.Lessor,
GrossAc = lease.Key.GrossAcres
}).Where(x => x.UnitId == unitId).OrderBy(x => x.TractId).ToList();
Thanks for help!!
Thanks for help!!
Thanks for help!!
Thanks for help!!
I modeled you query with classes to get syntax correct :
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
List<WorkingInterestGroups> workingInterestGroups = new List<WorkingInterestGroups>();
List<UnitTracts> unitTracts = new List<UnitTracts>();
List<Tracts> tracts = new List<Tracts>();
List<Leases> leases = new List<Leases>();
List<AdditionalLeaseInfo> additionalLeaseInfos = new List<AdditionalLeaseInfo>();
List<Interests> interests = new List<Interests>();
var results = (from unitTract in unitTracts
join tract in tracts on unitTract.TractId equals tract.Id
join interest in interests on tract.Id equals interest.TractId
join workingInterestGroup in workingInterestGroups on interest.WorkingInterestGroupId equals workingInterestGroup.Id
join lease in leases on workingInterestGroup.LeaseId equals lease.Id
join additionalLeaseInfo in additionalLeaseInfos on lease.Id equals additionalLeaseInfo.LeaseId
where unitTract.UnitId == "21"
select new { unitTract = unitTract, tract = tract, interest = interest, workingInterestGroup = workingInterestGroup,
lease = lease, additionalLeaseInfo = additionalLeaseInfo}).ToList();
var groups = results.GroupBy(x => new
{
x.unitTract.Id,
x.unitTract.UnitId,
x.lease.Lessor,
x.lease.Lessee,
x.lease.Alias,
x.lease.LeaseDate,
x.lease.GrossAcres,
x.lease.Legal,
x.interest.TractId,
x.lease.NetAcres,
x.unitTract.AcInUnit
})
.ToList();
}
}
public class WorkingInterestGroups
{
public string Id { get; set; }
public string LeaseId { get; set; }
}
public class UnitTracts
{
public string TractId { get; set; }
public string Id { get; set; }
public string UnitId { get; set; }
public string AcInUnit { get;set;}
}
public class Tracts
{
public string Id { get; set; }
}
public class Leases
{
public string Id { get; set; }
public string Lessor { get; set; }
public string Lessee { get; set; }
public string Alias { get; set; }
public string LeaseDate { get; set; }
public string GrossAcres { get; set; }
public string Legal { get; set; }
public string NetAcres { get; set; }
}
public class AdditionalLeaseInfo
{
public string LeaseId { get; set;}
}
public class Interests
{
public string TractId { get; set; }
public string WorkingInterestGroupId { get; set; }
}
}

Where is the mistake? Group by, join , select .net

I donĀ“t know where is the mistake why it says that does not contain a defintion of ImporteSolicitado, interesesDemora and importeReintegro when they are colums of c and the last one of d
var importes = (from c in _context.ReintegroSolicitado
join d in _context.ReintegroRecibido on c.Expediente.ID equals d.Expediente.ID
group new {c,d} by new { c.Expediente.Codigo} into cd
select new { ImporteSolictadoFinal = cd.Sum(b => b.ImporteSolicitado + b.InteresesDemora), ImporteReintegroFinal = cd.Sum(e => e.ImporteReintegro) });
your group element contains two property c and d. So you need refer to
this property as
...
select new {
ImporteSolictadoFinal = cd.Sum(b => b.c.ImporteSolicitado + b.c.InteresesDemora),
ImporteReintegroFinal = cd.Sum(e => e.d.ImporteReintegro) }
...
This is very tough to get right with query posted. I did my best, but it is probably not exactly correct.
var importes = (from c in _context.reintegroSolicitado
join d in _context.reintegroRecibido on c.expediente.ID equals d.expediente.ID
select new { reintegroSolicitado = c, reintegroRecibido = c})
.GroupBy(x => new { c = x.reintegroSolicitado , d = x.reintegroRecibido})
.Select(cd => new { ImporteSolictadoFinal = cd.Sum(b => b.reintegroSolicitado.ImporteSolicitado + b.reintegroSolicitado.InteresesDemora), ImporteReintegroFinal = cd.Sum(e => e.reintegroRecibido.ImporteReintegro) });
}
}
public class Context
{
public List<ReintegroSolicitado> reintegroSolicitado { get; set; }
public List<ReintegroSolicitado> reintegroRecibido { get; set; }
public Expediente expediente { get; set; }
}
public class ReintegroSolicitado
{
public Expediente expediente { get; set; }
public int ImporteSolicitado { get; set; }
public int InteresesDemora { get; set; }
public int ImporteReintegro { get; set; }
}
public class Expediente
{
public int ID { get; set; }
public int Codigo { get; set; }
}

LINQ query expressions and extension methods

How to make this expression using the methods of exptension, but (!) not using anonymous types?
from p in posts
join u in context.oxite_Users on p.CreatorUserID equals u.UserID
join pa in context.oxite_PostAreaRelationships on p.PostID equals pa.PostID
join a in context.oxite_Areas on pa.AreaID equals a.AreaID
let c = getCommentsQuery(p.PostID)
let t = getTagsQuery(p.PostID)
let tb = getTrackbacksQuery(p.PostID)
let f = getFilesQuery(p.PostID)
where p.State != (byte)EntityState.Removed
orderby p.PublishedDate descending
select new Post
{ area = a, comments = c } e.t.c.
The key here is to introduce a tuple that encapsulates the combined state of the join operations and other lets. I can't repro your environment just from that, but here's a limited example that should make it clear(ish);
using System.Linq;
static class Program
{
static void Main()
{
var users = new User[0]; // intentionally 0; only exists to prove compiles
var orders = new Order[0];
var query = users.Join(orders, user => user.UserId, order => order.OrderId, (user,order) => new UserOrderTuple(user,order))
.Where(tuple => tuple.State != 42).OrderByDescending(tuple => tuple.Order.OrderId)
.Select(tuple => new ResultTuple { Comment = tuple.Comment });
}
}
class ResultTuple
{
public string Comment { get; set; }
}
class UserOrderTuple
{
public UserOrderTuple(User user, Order order)
{
User = user;
Order = order;
Comment = "some magic that gets your comment and other let";
State = 124;
}
public string Comment { get; private set; }
public int State { get; private set; }
public User User { get; private set; }
public Order Order { get; private set; }
}
class User
{
public int UserId { get; set; }
}
class Order
{
public int UserId { get; set; }
public int OrderId { get; set; }
}

can't select into class using linq

I have a query that works fine when using an anonymous type but as soon as I try to un-anonymize it it fails to select all values into the class.
here is the linq i'm using (in combination with Subsonic 3):
var producten = (from p in Premy.All()
join pr in Producten.All() on p.dekking equals pr.ID
where p.kilometragemax >= 10000 &&
p.CCmin < 3000 &&
p.CCmax >= 3000 &&
p.leeftijdmax >= DateTime.Today.Subtract(car.datumEersteToelating).TotalDays / 365
group p by new { pr.ID, pr.Naam, pr.ShortDesc, pr.LongDesc } into d
select new
{
ID = d.Key.ID,
Dekking = d.Key.Naam,
ShortDesc = d.Key.ShortDesc,
LongDesc = d.Key.LongDesc,
PrijsAlgemeen = d.Min(x => x.premie),
PrijsAlgemeenMaand = d.Min(x => x.premie),
PrijsMerkdealerMaand = d.Min(x => x.premie),
PrijsMerkdealer = d.Min(x => x.premie)
}).ToList();
When I change it to:
List<QuotePremies> producten = (from p in Premy.All()
join pr in Producten.All() on p.dekking equals pr.ID
where p.kilometragemax >= 10000 &&
p.CCmin < 3000 &&
p.CCmax >= 3000 &&
p.leeftijdmax >= DateTime.Today.Subtract(car.datumEersteToelating).TotalDays / 365
group p by new { pr.ID, pr.Naam, pr.ShortDesc, pr.LongDesc } into d
select new QuotePremies
{
ID = d.Key.ID,
Dekking = d.Key.Naam,
ShortDesc = d.Key.ShortDesc,
LongDesc = d.Key.LongDesc,
PrijsAlgemeen = d.Min(x => x.premie),
PrijsAlgemeenMaand = d.Min(x => x.premie),
PrijsMerkdealerMaand = d.Min(x => x.premie),
PrijsMerkdealer = d.Min(x => x.premie)
}).ToList();
in combination with this class:
public class QuotePremies
{
public byte ID { get; set; }
public string Dekking { get; set; }
public string ShortDesc { get; set; }
public string LongDesc { get; set; }
public decimal PrijsAlgemeen { get; set; }
public decimal PrijsAlgemeenMaand { get; set; }
public decimal PrijsMerkdealer { get; set; }
public decimal PrijsMerkdealerMaand { get; set; }
}
it doesn't give me an error but all values in the class are 0 except for QuotePremies.ID, QuotePremies.ShortDesc and QuotePremies.LongDesc. No clue why that happens.
See if using conversion helps
PrijsAlgemeen = Convert.ToDecimal(d.Min(x => x.premie))
I believe the problem has to do with casting. Why not write and extension method for IEnumberable which would take this query result and return a collection of List. It could look something like this:
public static class Extensions
{
// extends IEnumerable to allow conversion to a custom type
public static TCollection ToMyCustomCollection<TCollection, T>(this IEnumerable<T> ienum)
where TCollection : IList<T>, new()
{
// create our new custom type to populate and return
TCollection collection = new TCollection();
// iterate over the enumeration
foreach (var item in ienum)
{
// add to our collection
collection.Add((T)item);
}
return collection;
}
}
Thanks to kek444 for helping me with a similar problem

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