Replace foreach to make loop into queryable - c#

I have a function returning a report object, but currently i am going through a foreach look and then using the asQueryable method.
I would like to do it in one query and not have to use the AsQueryable function.
var query = from item in context.Dealers
where item.ManufacturerId == manufacturerId
select item;
IList<DealerReport> list = new List<DealerReport>();
foreach (var deal in query)
{
foreach (var bodyshop in deal.Bodyshops1.Where(x => x.Manufacturer2Bodyshop.Select(s => s.ManufacturerId).Contains(manufacturerId)))
{
DealerReport report = new DealerReport();
report.Dealer = deal.Name;
report.Bodyshop = bodyshop.Name;
short stat = bodyshop.Manufacturer2Bodyshop.FirstOrDefault(x => x.ManufacturerId == manufacturerId).ComplianceStatus;
report.StatusShort = stat;
list.Add(report);
}
}
return list.OrderBy(x => x.Dealer).AsQueryable();

I think you want something like this:
var query = from deal in context.Dealers
where deal.ManufacturerId == manufacturerId
from bodyshop in deal.Bodyshops1
where bodyshop.Manufacturer2Bodyshop.Select(s => s.ManufacturerId).Contains(manufacturerId)
let stat = bodyshop.Manufacturer2Bodyshop.FirstOrDefault(x => x.ManufacturerId == manufacturerId)
orderby deal.Name
select new DealerReport
{
Dealer = deal.Name,
Bodyshop = bodyshop.Name,
StatusShort = stat != null ? stat.ComplianceStatus : 0, // or some other default
};
return query;

Related

C# Calculate field inside LINQ Query

I need some help to calculate a property inside my Linq query.
I know I need to use "let" somewhere, but I can't figure it out!
So, first I have this method to get my list from Database:
public BindingList<Builders> GetListBuilders()
{
BindingList<Builders> builderList = new BindingList<Builders>();
var ctx = new IWMJEntities();
var query = (from l in ctx.tblBuilders
select new Builders
{
ID = l.BuilderID,
Projeto = l.NomeProjeto,
Status = l.Status,
DataPedido = l.DataPedido,
DataPendente = l.DataPendente,
DataEntregue = l.DataEntregue,
DataAnulado = l.DataAnulado
});
foreach (var list in query)
builderList.Add(list);
return builderList;
}
Then, I have a function to calculate the Days between Dates accordingly to Status:
public int GetDays()
{
int Dias = 0;
foreach (var record in GetListBuilders)
{
if (record.Status == "Recebido")
{
Dias = GetBusinessDays(record.DataPedido, DateTime.Now);
}
else if (record.Status == "Pendente")
{
Dias = GetBusinessDays(record.DataPedido, (DateTime)record.DataPendente);
}
else if (record.Status == "Entregue")
{
Dias = GetBusinessDays(record.DataPedido, (DateTime)record.DataEntregue);
}
else if (record.Status == "Anulado")
{
Dias = GetBusinessDays(record.DataPedido, (DateTime)record.DataAnulado);
}
}
return Dias;
}
I need to call the GetDays in a DataGridView to give the days for each record.
My big problem is, How do I get this? include it in Linq Query? Calling GetDays() (need to pass the ID from each record to GetDays() function)!?
Any help?
Thanks
I think it would be easier to create an extension method:
public static int GetBusinessDays(this Builders builder) // or type of ctx.tblBuilders if not the same
{
if (builder == null) return 0;
switch(builder.status)
{
case "Recebido": return GetBusinessDays(builder.DataPedido, DateTime.Now);
case "Pendente": return GetBusinessDays(builder.DataPedido, (DateTime)builder.DataPendente);
case "Entregue": return GetBusinessDays(builder.DataPedido, (DateTime)builder.DataEntregue);
case "Anulado": GetBusinessDays(builder.DataPedido, (DateTime)builder.DataAnulado);
default: return 0;
}
}
Then, call it like that:
public BindingList<Builders> GetListBuilders()
{
BindingList<Builders> builderList = new BindingList<Builders>();
var ctx = new IWMJEntities();
var query = (from l in ctx.tblBuilders
select new Builders
{
ID = l.BuilderID,
Projeto = l.NomeProjeto,
Status = l.Status,
DataPedido = l.DataPedido,
DataPendente = l.DataPendente,
DataEntregue = l.DataEntregue,
DataAnulado = l.DataAnulado,
Dias = l.GetBusinessDays()
});
foreach (var list in query)
builderList.Add(list);
return builderList;
}
To do better, to convert a object to a new one, you should create a mapper.
Why does it need to be a part of the query? You can't execute C# code on the database. If you want the calculation to be done at the DB you could create a view.
You're query is executed as soon as the IQueryable is enumerated at the foreach loop. Why not just perform the calculation on each item as they are enumerated and set the property when you are adding each item to the list?

EF .Net Core Enumerable.Concat not working

Below is my code
var dbClaimLink = this.Context.Set<ClaimLink>();
var claims = await DbSet
.Include(claim => claim.Parent)
.Include(link => link.ParentLinks)
.ToListAsync();
var newClaimLink = await dbClaimLink.ToListAsync();
var processedClaims = claims.Select(x =>
{
var claimLinks = x.ParentLinks;
if (!claimLinks.Any())
{
return x;
}
var hiddenParents = claimLinks.Select(p => claims.Find(t => t.Id == p.ClaimLinkId));
x.HiddenParents = hiddenParents;
return x;
});
foreach (var objClaim in processedClaims)
{
if (objClaim.Children == null)
objClaim.Children = new List<Claim>();
var lst = newClaimLink.Where(k=> k.ClaimLinkId == objClaim.Id).ToList();
if (lst.Any())
{
foreach (var item in lst)
{
IEnumerable<Claim> newChildren = claims.Where(p => p.Id == item.ClaimId);
objClaim.Children.Concat(newChildren);
}
}
}
it always return old children set without concatenate with new children. I want to those old and new children set concatenate in side of foreach loop
the Concat method returns a new collection with both values and does not alter the original.
Concat will return new object - result of concatination, so you need to save it somewhere: var result = objClaim.Children.Concat(newChildren);
Where is lazy operation, it does not execute in place, only after materialization (ToArray, or foreach call): claims.Where(p => p.Id == item.ClaimId).ToArray()

How to sort in LINQ If Join other database

Sort in LINQ
I have 2 database CustomerEntities and BillEntities
I want to get CustomerName from CustomerEntities and sort it but it have no data and I want .ToList() just once time because it slow if used many .ToList()
using (var db1 = new CustomerEntities())
{ using (var db2 = new BillEntities())
{
var CustomerData = db1.Customer.Select(s=> new{s.CustomerCode,s.CustomerName}).ToList();
var BillData = (from t1 in db2.Bill
select new {
BillCode = t1.Billcode,
CustomerCode = t1.Customer,
CustomerName = ""; //have no data
});
}
if(sorting.status==true)
{
BillData= BillData.OrderBy(o=>o.CustomerName); //can't sort because CustomerName have no data
}
var data = BillData .Skip(sorting.start).Take(sorting.length).ToList(); // I want .ToList() just once time because it slow if used many .ToList()
foreach (var b in data)
{
var Customer = CustomerData.FirstOrDefault(f => f.CustomerCode==b.CustomerCode );
if(CustomerName>!=null)
{
r.CustomerName = Customer.CustomerName; //loop add data CustomerName
}
}
}
I have no idea to do it. Help me please
I'm not sure if I understand your code but what about this:
var BillData = (from t1 in db2.Bill
select new {
BillCode = t1.Billcode,
CustomerCode = t1.Customer,
CustomerName = db1.Customer.FirstOrDefault(c => c.CustormerCode == t1.Customer)?.CustomerName
});
Then you have objects in BillData that holds the CustomerName and you can order by that:
BillData.OrderBy(bd => bd.CustomerName);
If you just want to get CustomerName from your customer Db and sort it, this is what i would have used. I used orderByDescending but you can use OrderBy aswell.
public List<Customer> getLogsByCustomerName(string customername)
{
using (var dbentites = new CustomerEntities())
{
var result = (from res in dbentites.Customer.OrderByDescending(_ => _.CustomerName)
where res.CustomerName == customername
select res).ToList();
return result.ToList();
}
}

Optimization of nested loops using LINQ

Can you please suggest how to write an optmized LINQ query for the following operation?
foreach (DataRow entry1 in table1.Rows)
{
var columnA = entry1["ColumnA"] as string;
if (!string.IsNullOrEmpty(columnA))
{
foreach (string entry2 in table2)
{
var dataExists = table3.Any(rows3 =>
!string.IsNullOrEmpty(rows3[entry2] as string)
&& columnA.IsEqual(rows3["ColumnB"] as string));
if (dataExists)
{
entry1[entry2] = Compute(columnA, entry2);
}
}
}
}
I tried with this, but the results don't match in terms of the unique iteration counts.
var t2t3Pair = from entry2 in table2
let entry3 = table3.FirstOrDefault(x =>
!string.IsNullOrEmpty(x[entry2] as string))
where entry3 != null
select new { entry2, entry3 };
var t1t3Pair = from pair in t2t3Pair
from entry1 in table1.AsEnumerable()
let columnA = entry1["ColumnA"] as string
where !string.IsNullOrEmpty(columnA)
&& columnA.IsEqual(pair.entry3["ColumnB"] as string)
select new { Entry1Alias = entry1, Entry2Alias = pair.entry2 };
foreach (var pair in t1t3Pair)
{
var columnA = (string)pair.Entry1Alias["ColumnA"];
pair.Entry1Alias[pair.Entry2Alias] = Compute(columnA, pair.Entry2Alias);
}
Note: IsEqual is my extension method to compare string without case sensitivity.
Apparently the bottleneck is the line
var dataExists = table3.Any(rows3 =>
!string.IsNullOrEmpty(rows3[entry2] as string)
&& columnA.IsEqual(rows3["ColumnB"] as string));
which is executed inside the innermost loop.
As usual, it can be optimized by preparing in advance a fast lookup data structure and use it inside the critical loop.
For your case, I would suggest something like this:
var dataExistsMap = table3.AsEnumerable()
.GroupBy(r => r["ColumnB"] as string)
.Where(g => !string.IsNullOrEmpty(g.Key))
.ToDictionary(g => g.Key, g => new HashSet<string>(
table2.Where(e => g.Any(r => !string.IsNullOrEmpty(r[e] as string)))
// Include the proper comparer if your IsEqual method is using non default string comparison
//, StringComparer.OrdinalIgnoreCase
)
);
foreach (DataRow entry1 in table1.Rows)
{
var columnA = entry1["ColumnA"] as string;
if (string.IsNullOrEmpty(columnA)) continue;
HashSet<string> dataExistsSet;
if (!dataExistsMap.TryGetValue(columnA, out dataExistsSet)) continue;
foreach (string entry2 in table2.Where(dataExistsSet.Contains))
entry1[entry2] = Compute(columnA, entry2);
}

How to Filter linq query

I am able to filter the data with the following two parameters id1 and id2, and get accurate result of 10 records, from which have 9 with a price_type=cs and other with price-type=ms.
However, if I add price_type to the parameters id1 and id2 (id1=23456,567890&id2=6782345&price_type=ms), I get 3000 records instead of getting one record.
Am I missing something in the code. Any help would be very much appreciated.
var data = db.database_BWICs.AsQueryable();
var filteredData = new List<IQueryable<database_Data>>();
if (!string.IsNullOrEmpty(query.name))
{
var ids = query.name.Split(',');
foreach (string i in ids)
{
filteredData.Add(data.Where(c => c.Name != null && c.Name.Contains(i)));
}
}
if (!string.IsNullOrEmpty(query.id2))
{
var ids = query.id2.Split(',');
foreach (string i in ids)
{
filteredData.Add(data.Where(c => c.ID2!= null && c.ID2.Contains(i)));
}
}
if (!string.IsNullOrEmpty(query.id1))
{
var ids = query.id1.Split(',');
foreach (string i in ids)
{
filteredData.Add(data.Where(c => c.ID1!= null && c.ID1.Contains(i)));
}
}
if (query.price_type != null)
{
var ids = query.price_type.Split(',');
foreach (string i in ids)
{
filteredData.Add(data.Where(c => c.Type.Contains(i)));
}
}
if (filteredData.Count != 0)
{
data = filteredData.Aggregate(Queryable.Union);
}
Updated Code:
var data = db.database_BWICs.AsQueryable();
if (!string.IsNullOrEmpty(query.name))
{
var ids = query.name.Split(',');
data = data.Where(c => c.Name != null && ids.Contains(c.Name));
}
if (query.price_type != null)
{
var ids = query.price_type.Split(',');
data = data.Where(c => ids.Contains(c.Cover));
}
if (!String.IsNullOrEmpty(query.id1))
{
var ids = query.id1.Split(',');
data = data.Where(c => c.ID1!= null && ids.Contains(c.ID1));
}
Because you don't add filter to restrict, every filter adds datas to result.
It means you make OR between your filters, not AND.
And your usage of contains looks rather strange too : you're using String.Contains, while I would guess (maybe wrong) that you want to see if a value is in a list => Enumerable.Contains
You should rather go for something like this (withoud filteredData)
var data = db.database_BWICs.AsQueryable();
if (!string.IsNullOrEmpty(query.name))
{
var ids = query.name.Split(',');
data = data.Where(c => c.Name != null && ids.Contains(c.Name)));
}
//etc.
if (query.price_type != null)
{
var ids = query.price_type.Split(',');
data = data.Where(c => ids.Contains(c.Type));
}
EDIT
Well, if you wanna mix and or conditions, you could go for PredicateBuilder
Then your code should look like that (to be tested).
//manage the queries with OR clause first
var innerOr = Predicate.True<database_BWICs>();//or the real type of your entity
if (!String.IsNullOrEmpty(query.id1))
{
var ids = query.id1.Split(',');
innerOr = innerOr.Or(c => c.ID1!= null && ids.Contains(c.ID1));
}
if (!String.IsNullOrEmpty(query.id2))
{
var ids = query.id2.Split(',');
innerOr = innerOr.Or(c => c.ID2!= null && ids.Contains(c.ID2));
}
//now manage the queries with AND clauses
var innerAnd = Predicate.True<database_BWICs>();//or the real type of your entity
if (query.price_type != null)
{
var ids = query.price_type.Split(',');
innerAnd = innerAnd.And(c => ids.Contains(c.Type));
}
//etc.
innerAnd = innerAnd.And(innerOr);
var data = db.database_BWICs.AsQueryable().Where(innerAnd);

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