I have this query that I need to run:
IEnumerable<MerchantWithParameters> merchants =
from i in (
from m in d.GetTable<Merchant>()
join mtp in d.GetTable<MerchantToParameters>() on m.Id equals mtp.MerchantId into mtps
from mtp in mtps.DefaultIfEmpty()
join cp in d.GetTable<ContextParameters>() on mtp.ContextParametersId equals cp.Id into cps
from cp in cps.DefaultIfEmpty()
select new {Merchant = m, ContextParameter = cp}
)
group i by new { i.Merchant.Id } into ig
select new MerchantWithParameters()
{
Id = ig.Key.Id,
Parameters = ig.Where(g => g.ContextParameter != null).ToDictionary(g => g.ContextParameter.Key, g => g.ContextParameter.Text)
};
For some reason it takes really long time for this query to be completed.
I believe that it has something to do with
Parameters = ig.Where(g => g.ContextParameter != null).ToDictionary(g => g.ContextParameter.Key, g => g.ContextParameter.Text)
Because when I remove this line, query starts to execute really fast.
Could you please show me what am I doing wrong?
UPDATE:
I am using ToList() to extract data from the database.
It is known SQL limitation. You cannot get grouped items, only grouping key or aggregation result. Since you need all records, we can do grouping on the client side, but previously maximally limit retrieved data.
var query =
from m in d.GetTable<Merchant>()
from mtp in d.GetTable<MerchantToParameters>().LeftJoin(mtp => m.Id == mtp.MerchantId)
from cp in d.GetTable<ContextParameters>().LeftJoin(cp => mtp.ContextParametersId == cp.Id)
select new
{
MerchantId = m.Id,
ContextParameterKey = (int?)cp.Key,
ContextParameterText = cp.Text
};
var result =
from q in query.AsEnumerable()
group q by q.MerchantId into g
select new MerchantWithParameters
{
Id = g.Key,
Parameters = g.Where(g => g.ContextParameterKey != null)
.ToDictionary(g => g.ContextParameterKey.Value, g => g.ContextParameterText)
};
var merchants = result.ToList();
I'm joining two data tables on composite key i.e account no. and amount but according pictures I've attached I'm getting only one row after join but I should get 2 rows.
var query = from dataRows1 in clearingDTAlias.AsEnumerable()
join dataRows2 in excelDT.AsEnumerable()
on new
{
Account_No = dataRows1.Field<string>("Account_No"),
Amount = dataRows1.Field<string>("Withdraw_Amount_Requested")
} equals new
{
Account_No = dataRows2.Field<string>("Account_No"),
Amount = dataRows2.Field<string>("Amount")
}
select joinDT.LoadDataRow(new object[]
{
dataRows2.Field<string>("Account_No"),
dataRows2.Field<string>("Amount"),
dataRows2.Field<string>("Code"),
dataRows2.Field<string>("Row_No"),
}, true);
if (query.Any())
{
var query2 = query.GroupBy(test => test.Field<string>("Row_No")).Select(grp => grp.First()).ToList();
if (query2.Any())
joinDT = query2.CopyToDataTable();
else
joinDT = excelDT.Clone();
}
Use below group by clause to get the grouped rows from query.
var query2 = query.GroupBy(test => test.Field<string>("Row_No"))
.Select(grp => grp.Key).ToList()
Actually I want to return the data from different lists based on Date. When i'm using this i'm getting data upto #Var result but i'm unnable to return the data. The issue with this is i'm getting error #return result. I want to return the data #return result. I'm using Linq C#. Can anyone help me out?
public List<CustomerWiseMonthlySalesReportDetails> GetAllCustomerWiseMonthlySalesReportCustomer()
{
var cbsalesreeport = (from cb in db.cashbilldescriptions
join c in db.cashbills on cb.CashbillId equals c.CashbillId
join p in db.products on cb.ProductId equals p.ProductId
select new
{
Productamount = cb.Productamount,
ProductName = p.ProductDescription,
CashbillDate = c.Date
}).AsEnumerable().Select(x => new ASZ.AmoghGases.Model.CustomerWiseMonthlySalesReportDetails
{
Productdescription = x.ProductName,
Alldates = x.CashbillDate,
TotalAmount = x.Productamount
}).ToList();
var invsalesreeport = (from inv in db.invoices
join invd in db.invoicedeliverychallans on inv.InvoiceId equals invd.InvoiceId
select new
{
Productamount = invd.Total,
ProductName = invd.Productdescription,
InvoiceDate = inv.Date
}).AsEnumerable().Select(x => new ASZ.AmoghGases.Model.CustomerWiseMonthlySalesReportDetails
{
Productdescription = x.ProductName,
Alldates = x.InvoiceDate,
TotalAmount = x.Productamount
}).ToList();
var abc = cbsalesreeport.Union(invsalesreeport).ToList();
var result = (from i in abc
group i by new { Date = i.Alldates.ToString("MMM"), Product = i.Productdescription } into grp
select new { Month = grp.Key, Total = grp.Sum(i => i.TotalAmount) });
**return result;**
}
You can either convert your result to a List before returning it using return result.ToList() or make your method return an IEnumerable<CustomerWiseMonthlySalesReportDetails> instead of List.
As your result is an enumeration of anonymous types you have to convert them to your CustomerWiseMonthlySalesReportDetails-type first:
select new CustomerWiseMonthlySalesReportDetails{ Month = grp.Key, Total = grp.Sum(i => i.TotalAmount) });
Assuming your type has exactly the members returned by the select.
EDIT: So your code should look like this:
var result = (from i in abc
group i by new { Date = i.Alldates.ToString("MMM"), Product = i.Productdescription } into grp
select new CustomerWiseMonthlySalesReportDetails{ Month = grp.Key, Total = grp.Sum(i => i.TotalAmount) });
return result.ToList();
You can assume Alldates property if is date of one of groups that month of date is in right place:
var result = (from i in abc
group i by new { Date = i.Alldates.ToString("MMM"), Product = i.Productdescription }
into grp
select new CustomerWiseMonthlySalesReportDetails{
Productdescription = grp.Key.Product,
TotalAmount = grp.Sum(i => i.TotalAmount),
Alldates =grp.First(i=>i.Alldates ) })
.ToList();
I have the following SQL that I would like to write as a single linq statement:
SELECT
P.PartyId,
P.PartyDate,
SUM(COALESCE(R.PaidAmount, 0)) AS AmountPaid
FROM
Party AS P
LEFT JOIN Reservation as R
ON P.PartyID = R.PartyID
GROUP BY P.PartyID, P.PartyDate
ORDER BY P.PartyDate DESC
The best I can do is use two sets of linq queries, like so:
var localList = from partyList in localDb.Parties
join reservationList in localDb.Reservations on
partyList.PartyID equals reservationList.PartyID into comboList
from newList in comboList.DefaultIfEmpty()
select new PartyAmounts {
PartyID = partyList.PartyID,
PartyDate = partyList.PartyDate,
AmountPaid = (newList.PaidAmount ?? 0) };
var secondList = from groupList in localList
group groupList by new {
groupList.PartyID,
groupList.PartyDate} into resList
select new PartyAmounts {
PartyID = resList.Key.PartyID,
PartyDate=resList.Key.PartyDate,
AmountPaid = resList.Sum(x => x.AmountPaid)};
I don't care if it's a method chain or a lambda but I would love to know how this is supposed to go together. I can only barely understand the two I've got now.
Thanks for the help.
var list = from partyList in localDb.Parties
join reservationList in localDb.Reservations on partyList.PartyID equals reservationList.PartyID into comboList
from details in comboList.DefaultIfEmpty() // Left join
group details by new {partyList.PartyID, partyList.PartyDate} into grouped // So that the group have both keys and all items in details
select new PartyAmounts
{
PartyID = grouped.Key.PartyID,
PartyDate = grouped.Key.PartyDate,
AmountPaid = grouped.Sum(x => x.AmountPaid ?? 0)}
};
Hi i have the following code to select data from one table not in other table
var result1 = (from e in db.Users
select e).ToList();
var result2 = (from e in db.Fi
select e).ToList();
List<string> listString = (from e in result1
where !(from m in result2
select m.UserID).Contains(e.UserID)
select e.UserName).ToList();
ViewBag.ddlUserId = listString;
Am getting value inside listString .But got error while adding listString to viewbag.
Unable to cast object of type 'System.Collections.Generic.List`1[System.String]' to type 'System.Collections.Generic.IEnumerable`1[Main.Models.Admin.User]'.
First, could you update your question with the entire method so that we can see what might be going on with the ViewBag? Because your code should work just fine, assigning whatever value to the ViewBag is no problem normally:
ViewBag.property1 = 0;
ViewBag.property1 = "zero";
works just fine. ViewBag is dynamic. Now, you could get that error if you would later try to assing ViewBag.ddlUserId to something that actually is the wrong type.
I would like you to rewrite your statement as well, let me explain why. Assume for a moment that you have a lot ( > 100.000) of User records in your db.Users and we assume the same for Fi as well. In your code, result1 and result2 are now two lists, one containing >100.000 User objects and the other >100.000 Fi objects. Then these two lists are compared to each other to produce a list of strings. Now imagine the resource required for your web server to process this. Under the assumption that your actually using/accessing a separate SQL server to retrieve your data from, it would be a lot better and faster to let that server do the work, i.e. producing the list of UserID's.
For that you'd either use Kirill Bestemyanov's answer or the following:
var list = (from user in db.Users
where !db.Fi.Any(f => f.UserID == user.UserID)
select user.UserName).ToList()
This will produce just one query for the SQL server to execute:
SELECT
[Extent1].[UserName] AS [UserName]
FROM [dbo].[Users] AS [Extent1]
WHERE NOT EXISTS (SELECT
1 AS [C1]
FROM [dbo].[Fi] AS [Extent2]
WHERE [Extent2].[UserID] = [Extent1].[UserID]
)}
which in the end is what you want...
Just to clarify more:
var list = (from user in db.Users
where !db.Fi.Any(f => f.UserID == user.UserID)
select user.UserName).ToList()
can be written as the following lambda expression as well:
var list = db.Users.Where(user => !db.Fi.Any(f => f.UserID == user.UserID))
.Select(user => user.UserName).ToList()
which from the looks of it is slightly different from Kirill Bestemyanov's answer (which I slightly modified, just to make it look more similar):
var list = db.Users.Where(user => !db.Fi.Select(f => f.UserID)
.Contains(user.UserID))
.Select(user => user.UserName).ToList();
But, they will in fact produce the same SQL Statement, thus the same list.
I will rewrite it to linq extension methods:
List<string> listString = db.Users.Where(e=>!db.Fi.Select(m=>m.UserID)
.Contains(e.UserID))
.Select(e=>e.UserName).ToList();
try it, it should work.
Try this it is very simple.
var result=(from e in db.Users
select e.UserID).Except(from m in db.Fi
select m.UserID).ToList();
var res = db.tbl_Ware.where(a => a.tbl_Buy.Where(c => c.tbl_Ware.Title.Contains(mtrTxtWareTitle.Text)).Select(b => b.Ware_ID).Contains(a.ID));
This mean in T-SQL is:
SELECT * FROM tbl_Ware WHERE id IN (SELECT ware_ID, tbl_Buy WHErE tbl_Ware.title LIKE '% mtrTxtwareTitle.Text %')
getdata = (from obj in db.TblManageBranches
join objcountr in db.TblManageCountries on obj.Country equals objcountr.iCountryId.ToString() into objcount
from objcountry in objcount.DefaultIfEmpty()
where obj.IsActive == true
select new BranchDetails
{
iBranchId = obj.iBranchId,
vBranchName = obj.vBranchName,
Addressline1 = obj.Addressline1,
Adminemailid = obj.Adminemailid,
BranchType = obj.BranchType,
Country = objcountry.vCountryName,
CreatedBy = obj.CreatedBy,
CreatedDate = obj.CreatedDate,
iArea = obj.iArea,
iCity = obj.iCity,
Infoemailid = obj.Infoemailid,
Landlineno = obj.Landlineno,
Mobileno = obj.Mobileno,
iState = obj.iState,
Pincode = obj.Pincode,
Processemailid = obj.Processemailid,
objbranchbankdetails = (from objb in db.TblBranchesBankDetails.Where(x => x.IsActive == true && x.iBranchId == obj.iBranchId)
select new ManageBranchBankDetails
{
iBranchId = objb.iBranchId,
iAccountName = objb.iAccountName,
iAccountNo = objb.iAccountNo,
iBankName = objb.iBankName,
iAccountType = objb.iAccountType,
IFSCCode = objb.IFSCCode,
SWIFTCode = objb.SWIFTCode,
CreatedDate = objb.CreatedDate,
Id = objb.Id
}).FirstOrDefault(),
objbranchcontactperson = (from objc in db.tblbranchcontactpersons.Where(x => x.Isactive == true && x.branchid == obj.iBranchId)
select new ManageBranchContactPerson
{
branchid = objc.branchid,
createdate = objc.createdate,
Id = objc.Id,
iemailid = objc.iemailid,
ifirstname = objc.ifirstname,
ilandlineno = objc.ilandlineno,
ilastname = objc.ilastname,
imobileno = objc.imobileno,
title = objc.title,
updateddate=objc.updateddate,
}).ToList(),
}).OrderByDescending(x => x.iBranchId).ToList();
getdata = (from obj in db.TblManageBranches join objcountr in db.TblManageCountries on obj.Country equals objcountr.iCountryId.ToString() into objcount from objcountry in objcount.DefaultIfEmpty() where obj.IsActive == true
select new BranchDetails
{
iBranchId = obj.iBranchId,
vBranchName = obj.vBranchName,
objbranchbankdetails = (from objb in db.TblBranchesBankDetails.Where(x => x.IsActive == true && x.iBranchId == obj.iBranchId)
select new ManageBranchBankDetails
{
iBranchId = objb.iBranchId,
iAccountName = objb.iAccountName,
}).FirstOrDefault(),
objbranchcontactperson = (from objc in db.tblbranchcontactpersons.Where(x => x.Isactive == true && x.branchid == obj.iBranchId)
select new ManageBranchContactPerson
{
branchid = objc.branchid,
createdate = objc.createdate,
Id = objc.Id,
iemailid = objc.iemailid,
}).ToList(),
}).OrderByDescending(x => x.iBranchId).ToList();