This is the working query i was using in my management studio.
SELECT TOP 5 productCode, SUM(productSales) AS sales
FROM sellingLog
WHERE (salesYear = '2014')
GROUP BY productCode
ORDER BY sales DESC
I want to convert the query above into lambda, but i can't seems to make it works. the lambda still lacks of order by and select the productCode
var topProducts = sellingLog
.Where(s => s.salesYear == 2014)
.GroupBy(u => u.productCode)
.Select(b => b.Sum(u => u.productSales)).Take(5)
.ToList();
foreach(var v in topProduct)
{
//reading 'productCode' and 'sales' from each row
}
var topProducts = sellingLog
.Where(s => s.salesYear == 2014)
.GroupBy(u => u.productCode)
.Select(g => new { productCode = g.Key, sales = g.Sum(u => u.productSales) })
.OrderByDescending(x => x.productCode)
.Take(5)
.ToList();
You can use the .Key with group by to get productCode
var topProducts = sellingLog
.Where(s => s.salesYear == 2014)
.GroupBy(u => u.productCode)
.Select(b => new {u.Key, b.Sum(u => u.productSales)}).Take(5)
.OrderByDescending(b=>b.Sales)
.ToList();
Related
I am using Xamarin c# linq with sqlite-net pcl (https://github.com/praeclarum/sqlite-net). I found that all my linq groupby cannot be properly translated into SQL. Linq translates the Where clause but not Group By.
In the following example, the fields used in Transaction:
AccountId: int
Amount: double
ICategoryId: int
All these query formats result in SQL without Group By:
select * from "Transaction" where ("DateWithoutTime" <= ?)
var accountBalances1 = _dataService.Connection.Table<Transaction>()
.Where(r => r.DateWithoutTime <= displayDuration.DurationEnd)
.GroupBy(r => r.AccountId)
.Select(g => new
{
Id = g.Key,
Balance = g.Sum(b => b.Amount)
})
.ToList();
var accountBalances2 = _dataService.Connection.Table<Transaction>()
.Where(r => r.DateWithoutTime <= displayDuration.DurationEnd)
.GroupBy(r => r.AccountId,
(key, g) => new
{
Id = key,
Balance = g.Sum(b => b.Amount),
})
.ToList();
var accountBalances3 = (from t in _dataService.Connection.Table<Transaction>()
where t.DateWithoutTime <= displayDuration.DurationEnd
group t by t.AccountId
into g
select new { g.Key, Balance = g.Sum(g => g.Amount) })
.ToList();
To clarify it has nothing to do with double data type, I tried another group by with int data type only:
var maxIECategoryId = _dataService.Connection.Table<Transaction>()
.Where(r => r.DateWithoutTime <= displayDuration.DurationEnd)
.GroupBy(r => r.AccountId,
(key, g) => new
{
Id = key,
IECategoryId = g.Max(b => b.IECategoryId)
})
.ToList();
Similarly, the generated sql does not have group by.
All group by are processed locally. Is there any trick to write a linq group by that can be processed on the server service? or it is a limitation of this implementation of sqlite orm?
Thanks,
Nick
MySQL Query
select MAX(os.aggregate_date) as lastMonthDay,os.totalYTD
from (SELECT aggregate_date,Sum(YTD) AS totalYTD
FROM tbl_aggregated_tables
WHERE subscription_type = 'Subcription Income'
GROUP BY aggregate_date) as os
GROUP by MONTH(os.aggregate_date),YEAR(os.aggregate_date)
ORDER BY lastMonthDay;
converted to this LINQ query
var income = context.tbl_aggregated_tables
.Where(s => s.subscription_type == "Subcription Income")
.GroupBy(s => s.aggregate_date)
.Select(result => new
{
date = result.Key,
ytdsum = result.Select(x => x.YTD).Sum()
})
.GroupBy(s => new { month = s.date.Month, year = s.date.Year })
.Select(
// select max data and take its ytdsum value
).ToList();
The purpose of second grouping is to find the max day of each month with a year.
Now, How to select the max date of each month and its ytdsum after the second Grouping?
update
income = context.tbl_aggregated_tables
.Where(s => s.subscription_type == "Subcription Income")
.GroupBy(s => s.aggregate_date)
.Select(result => new
{
date = result.Key,
ytdsum = result.Select(x => x.YTD).Sum()
})
.GroupBy(s => new { s.date.Month, s.date.Year })
.Select(
x => x.Max(s => s.date)
).ToList()
this way it's only return the dates and i could not return the full object of the list including ytdSum.
This should work:
var income = context.tbl_aggregated_tables
.Where(s => s.subscription_type == "Subcription Income")
.GroupBy(s => s.aggregate_date)
.Select(result => new
{
date = result.Key,
ytdsum = result.Select(x => x.YTD).Sum()
})
.GroupBy(s => new { month = s.date.Month, year = s.date.Year })
.Select(
x => x.OrderByDescending(k => k.date).First()
).ToList();
income now is a list of objects, each of them have date and ytdsum
this worked good but it takes much more time than the original mysql query.
var income = context.tbl_aggregated_tables
.Where(s => s.subscription_type == "Subcription Income"
)
.GroupBy(s => s.aggregate_date)
.Select(result => new
{
date = result.Key,
ytdsum = result.Select(x => x.YTD).Sum()
})
.GroupBy(s => new { s.date.Month, s.date.Year })
.Select(
x => x.OrderByDescending(s => s.date)
)
.ToList()
.Select(el => el.FirstOrDefault())
.OrderBy(s=>s.date);
I have this Linq query:
var area = db.MyDbSet
.Where(s => s.langid == langid)
.GroupBy(s => s.Title)
.Select(g => new { Title = g.Key })
.Select(s => s.Title);
I want to return another column from the same table, its called: CodeId.
I am noob Linq programmer and quite lost in all those mish-mash things in C# so I can't really understand what should I do.
Can somebody help me how to return the another column from the same table with the same query call?
This may help you :
var area = db.MyDbSet
.Where(s => s.langid == langid)
.GroupBy(s => s.Title)
.Select(g => new { Title = g.Key, CodeId = g.FirstOrDefault().CodeId });
var area = db.MyDbSet
.Where(s => s.langid == langid)
.GroupBy(s => s.Title)
.Select(g => new {
Title = g.Key,
CodeId = g.Id,
OtherField = "Field"
})
I need to convert the following SQL query to Linq :-
SELECT CODE,SCODE,MAX(SDATE) AS SDATE FROM SHIFTSCHEDULE
WHERE COMPANY = 'ABC'
GROUP BY CODE,SCODE
ORDER BY MAX(SDATE)
DESC
So far, I have tried this :-
var data = ctx.ShiftSchedule.Where(m =>
m.Company == company && m.EmployeeId == item.EmployeeId
)
.GroupBy(m =>
new
{
m.EmployeeId,
m.ShiftId
})
.Select(m =>
new
{
EmployeeId = m.Key.EmployeeId,
ShiftCode = m.Key.ShiftId,
ShiftDate = m.Max(gg => gg.ShiftDate)
}).ToList();
The results i get are :-
Now what i want is to get record or item in this result set which is MaxDate. In the above image the MaxDate is 1st record.
How to get the MAXDATE from the resultset?
This should work:-
var data = ctx.ShiftSchedule.Where(x => x.Company == company
&& x.EmployeeId == item.EmployeeId)
.GroupBy(x => new { x.CODE, x.SCODE })
.Select(x => new
{
CODE = x.Key.CODE,
SCODE = x.Key.SCODE,
SDATE = x.Max(z => z.SDATE)
})
.OrderByDescending(x => x.SDATE).FirstOrDefault();
You can order the resulting collection and fetch the first object using FirstOrDefault.
If you want just MAXDATE, you can only project that.
Just add .OrderByDescending(x => x.ShiftDate).First(); at the end.
OrderByDescending date and then take .First()
var data = ctx.ShiftSchedule.Where(m =>
m.Company == company && m.EmployeeId == item.EmployeeId
)
.GroupBy(m =>
new
{
m.EmployeeId,
m.ShiftId
})
.Select(m =>
new
{
EmployeeId = m.Key.EmployeeId,
ShiftCode = m.Key.ShiftId,
ShiftDate = m.Max(gg => gg.ShiftDate)
}).ToList().OrderByDescending(x => x.ShiftDate).First();
I'm using this query to count number of orders by date. I'm trying to add one more parameter that counts total products for each order, however I can't get it to work atm.
This is the essential part of a method that is suposed to return a list of 3 parameters (Date, TotalOrders and TotalProducts). Im using a Linq query to get a list with total order for each date, im wondering how to add my third parameter to the list "TotalProducts" and if i can do by adding one more search parameter in the Query. The foreach part below do not work propertly, it will return a list of TotalProducts but CreationDate will be the same for ech item in the list. I also have a feeling putting a foreach inside a foreach dosn't seem optimal for this:
var orders = _orderService.SearchOrderStatistics(startDateValue, endDateValue, orderStatus,
paymentStatus, shippingStatus, model.CustomerEmail, model.OrderGuid);
var result = orders.Where(o => o.PaymentStatus == PaymentStatus.Paid)
.GroupBy(g => g.CreatedOnUtc.Date.ToString("yyyyMMdd"))
.Select(s => new { Date = s.Key, Count = s.Count() });
List<GCOrdersModel> TotalOrdersPaid = new List<GCOrdersModel>();
foreach (var g in result)
{
foreach (var opv in orders)
{
GCOrdersModel _Om = new GCOrdersModel(g.Date, g.Count.ToString(), opv.OrderProductVariants.Count.ToString());
TotalOrdersPaid.Add(_Om);
}
}
return TotalOrdersPaid;
To access total products for every orders I must use OrderProductVariants.Count.ToString()
Can I add this parameter to the query?
Thx
You could try this:
return orders.Where(o => o.PaymentStatus == PaymentStatus.Paid)
.GroupBy(g => g.CreatedOnUtc.Date.ToString("yyyyMMdd"))
.Select(s => new GCOrdersModel()
{
Date = s.Key,
Count = s.Count(),
OpvCount = opv.OrderProductVariants.Count.ToString()
})
.ToList();
or
return orders.Where(o => o.PaymentStatus == PaymentStatus.Paid)
.GroupBy(g => g.CreatedOnUtc.Date.ToString("yyyyMMdd"))
.Select(s => new GCOrdersModel(s.Key, s.Count, opv.OrderProductVariants.Count.ToString()))
.ToList();
That way, you don't have to iterate over your result again. And it automatically creates your list of GCOrdersModel.
Edit
Does this work?
return orders.Where(o => o.PaymentStatus == PaymentStatus.Paid)
.GroupBy(g => g.CreatedOnUtc.Date.ToString("yyyyMMdd"))
.Select(s => new GCOrdersModel()
{
Date = s.Key,
Count = s.Count(),
OpvCount = s.OrderProductVariants.Count.ToString()
})
.ToList();
or
return orders.Where(o => o.PaymentStatus == PaymentStatus.Paid)
.GroupBy(g => g.CreatedOnUtc.Date.ToString("yyyyMMdd"))
.Select(s => new GCOrdersModel(s.Key, s.Count(), s.OrderProductVariants.Count.ToString()))
.ToList();
How about:
var opvCount =
opv
.OrderProductVariants
.Count
.ToString();
return
orders
.Where(o => o.PaymentStatus == PaymentStatus.Paid)
.GroupBy(g => g.CreatedOnUtc.Date.ToString("yyyyMMdd"))
.Select(s => new
{
Date = s.Key,
Count = s.Count()
})
.Select(x =>
new GCOrdersModelg(x.Date, g.Count.ToString(), opvCount));