how to use group by in Linq.
SqlServer Sample
select
ActionGroupName,
sum(cast(isnull(solicit_count,0) as int)) as 'SolicitCount'
from
[solicits]
group by
ActionGroupName
my linq version
var groupbyfilter = from v in lstSale
group v by v.ActionGroupName into g
select g.ActionGroupName, sum(g.solicit_count)
i am not getting it in proper way.
Try:
var groupbyfilter = from v in lstSale
group v by v.ActionGroupName into g
select new
{
ActionGroupName = g.Key,
Sum = g.Sum(x => x.solicit_count)
};
Related
I have a query which is connecting two tables that is header and detail table and in the having clause i have to check whether total mark of the header should equal to the sum of the detail marks.
Query is :-
select h.ExamID,h.ExamID,max(h.TotalMark) as TotalMark
from ExamMasters h
join ExamDetails d on h.ExamID=d.ExamID
group by h.ExamID,h.ExamName
having max(h.TotalMark)=sum(d.Mark)
I just want to convert this query to linq syntax.
Can anybody help please.
Regards,
Ajith
It should be:
var res = from h in ExamMasters
join d in ExamDetails on h.ExamID equals d.ExamID
group new { h, d } by new { h.ExamID, h.ExamName } into hdg
let max = hdg.Max(x => x.h.TotalMark)
where hdg.Sum(x => x.d.Mark) == max
select new
{
hdg.Key.ExamID, hdg.Key.ExamName, TotalMark = max
};
Note the use of group ... by ... into and the fact that to have both h and d after the group by I had to put them in a new { h, d }.
I'm having trouble getting my Linq statemnt to work when doing an outer join and a group by. Here's a SQL version of what I'm trying to accomplish:
select p.PRIMARY_KEY, min(p.EFFECTIVE_DATE), sum(IsNull(c.PAID_INDEMNITY, 0))
from PRMPOLCY p
left outer join CLMMAST c on p.PRIMARY_KEY = c.POLICY_NO
where p.UNDERWRITER_UID = 93
GROUP BY p.PRIMARY_KEY
Here's what I have in Linq (which doesn't work):
var result = from p in context.PRMPOLCies
join c in context.CLMMASTs on p.PRIMARY_KEY equals c.POLICY_NO into polClm
where (p.UNDERWRITER_UID == underwriter)
from grp in polClm.DefaultIfEmpty()
group grp by p.PRIMARY_KEY into g
select new PolicySummation()
{
PolicyNo = g.Key,
Incurred = g.Sum(grp => grp.PAID_INDEMNITY ),
EffDate = g.Min(grp => grp.PRMPOLCY.EFFECTIVE_DATE
};
Beating my head against the wall trying to figurwe this out!
Assuming you have a navigation property set up between PRMPOLCY and CLMMAST, you shouldn't need to specify the join explicitly. It's much easier to express most queries in linq without explicit joins, but rather treating your structures as a hierarchy. I don't know the specifics of your model property names, but I'd take a guess that something like this would work.
var result =
from p in context.PRMPOLCies
where (p.UNDERWRITER_UID == underwriter)
select new PolicySummation {
PolicyNo = p.PRIMARY_KEY,
Incurred = p.CLMASTs.Select(c => c.PAID_INDEMNITY).DefaultIfEmpty().Sum(),
EffDate = p.EFFECTIVE_DATE,
};
You need to include both your tables in the group clause like this:
group new { p, grp } by p.PRIMARY_KEY into g
Then in your Sum / Min
g.Sum(grp => grp.grp == null ? 0 : grp.grp.PAID_INDEMNITY )
g.Min(grp => grp.p.PRMPOLCY.EFFECTIVE_DATE)
var abc1 = from dlist in db.DebtorTransactions.ToList()
join war in db.Warranties on dlist.ProductID equals war.Id
join ag in db.Agents on war.fldAgentID equals ag.pkfAgentID
join sr in db.SalesReps on war.fldSrId equals sr.pkfSrID
where dlist.TransTypeID == 1
select new
{
dlist.Amount,
dlist.TransTypeID,
name = ag.Name,
ag.pkfAgentID,
sr.pkfSrID,
salesnam = sr.Name
} into objabc
group objabc by new
{
objabc.TransTypeID,
objabc.name,
objabc.salesnam,
objabc.Amount
};
var amt1 = abc1.Sum(x => x.Key.Amount);
var abc2 = from dlist in db.DebtorTransactions.ToList()
join cjt in db.CarJackaTrackas on dlist.ProductID equals cjt.pkfCjtID
join ag in db.Agents on cjt.AgentID equals ag.pkfAgentID
join sr in db.SalesReps on cjt.SalesRepId equals sr.pkfSrID
where dlist.TransTypeID == 0
select new
{
dlist.Amount,
dlist.TransTypeID,
name = ag.Name,
ag.pkfAgentID,
sr.pkfSrID,
enter code here` salesnam = sr.Name
} into objabc
group objabc by new
{
objabc.TransTypeID,
objabc.name,
objabc.salesnam,
objabc.Amount
};
var amt2 = abc1.Sum(x => x.Key.Amount);
//var result1=
return View();
i am new to linq, this query is working but i need to get the sum of Amount where dlist.TransTypeID == 0 and where dlist.TransTypeID == 1 by just single query. may anybody help me? thanks in advance
Here's a trimmed down example of how you can do it. You can add the joins if they are necessary, but I'm not clear on why you need some of the extra join values.
var transTypeAmountSums = (from dlist in db.DebtorTransactions
group dlist by dlist.TransTypeId into g
where g.Key == 0 || g.Key == 1
select new
{
TransTypeId = g.Key,
AmountSum = g.Sum(d => d.Amount)
}).ToDictionary(k => k.TransTypeId, v => v.AmountSum);
int transTypeZeroSum = transTypeAmountSums[0];
int transTypeOneSum = transTypeAmountSums[1];
A couple of things to note:
I removed ToList(). Unless you want to bring ALL DebtorTransactions into memory then run a Linq operation on those results, you'll want to leave that out and let SQL take care of the aggregation (it's much better at it than C#).
I grouped by dlist.TransTypeId only. You can still group by more fields if you need that, but it was unclear in the example why they were needed so I just made a simplified example.
I am trying to do a relatively straight forward SQL query with linq:
SELECT ir.resource_id, r.first_name, r.surname, rt.job_title, SUM(plan_ts_hours), SUM(ts_hours) FROM tbl_initiative_resource ir
INNER JOIN tbl_resource r ON ir.resource_id = r.resource_id
INNER JOIN tbl_resource_type rt ON rt.resource_type_id = r.resource_type_id
LEFT JOIN tbl_plan_timesheet pts on pts.resource_id = ir.resource_id AND pts.initiative_id = ir.initiative_id
LEFT JOIN tbl_timesheet ts on ts.resource_id = ir.resource_id AND ts.initiative_id = ir.initiative_id
WHERE ir.initiative_id = 111
GROUP BY ir.resource_id, r.first_name, r.surname, rt.job_title
After reading this blog: http://smehrozalam.wordpress.com/2010/04/06/linq-how-to-build-complex-queries-utilizing-deferred-execution-and-anonymous-types/
I came up with the following linq:
var query = (from initRes in Context.tbl_initiative_resource
join res in Context.tbl_resource on initRes.resource_id equals res.resource_id
join resType in Context.tbl_resource_type on res.resource_type_id equals resType.resource_type_id
from tsheet in Context.tbl_timesheet.Where(x => x.resource_id == initRes.resource_id).Where(x => x.initiative_id == initRes.initiative_id).DefaultIfEmpty()
from plannedtsheet in Context.tbl_plan_timesheet.Where(x => x.resource_id == initRes.resource_id).Where(x => x.initiative_id == initRes.initiative_id).DefaultIfEmpty()
where initRes.initiative_id == initiativeID
group new { ID = res.resource_id, ResourceType = resType.job_title, Times = tsheet, P = plannedtsheet } by initRes.resource_id into g
select new
{
ResourceID = g.Key,
Hours = g.Sum(x => (decimal?)x.Times.ts_hours),
PlannedHours = g.Sum(x => (decimal?)x.P.plan_ts_hours)
}).ToList();
Any ideas on how I can access the ResourceType when selecting the new anonymous type?
ResourceType is part of the the grouping key, so g.Key.ResourceType should do it.
(Check out the type of ResouceID in the results, as you've assigned it g.Key it will be an instance of the (anonymous) type created in the group clause.
i have this simple SQL query...
-- BestSeller
SELECT TOP(1) v.make, v.model, COUNT(v.make) AS NoSold
FROM Vehicles v
group by v.make, v.model
order by NoSold DESC
Im using entity framwork and want to do the same thing using linq. so far i have...
var tester = (from v in DB.VP_Historical_Vehicles
group v by v.make into g
orderby g.Count() descending
select new { make = g.Key, model = g, count = g.Count() }).Take(1);
foreach(var t in tester)
{
BestSeller.Make = t.make;
BestSeller.Model = t.make;
BestSeller.CountValue = t.count;
}
i keep getting timeouts, the database is large but the SQL runs very quick
any sugestions?
thanks
truegilly
Group by a compound key.
var t = (
from v in DB.VP_Historical_Vehicles
group v by new { v.make, v.model } into g
orderby g.Count() descending
select new { make = g.Key.make, model = g.Key.model, count = g.Count() }
)
.First();
BestSeller.Make = t.make;
BestSeller.Model = t.make;
BestSeller.CountValue = t.count;
Check what queries it performs when you run it with LINQ.
I suspect that you orderby g.Count() descending might be executing a COUNT query for each row and that would take a toll on performance to say the least.
When working with EF, always check what your LINQ statements produce in terms of queries. It is very easy to create queries that result in a n+1 scenario.
thanks to Scott Weinstein answer i was able to get it working
please comment if there is a more efficiant way of doing this...
VehicleStatsObject BestSeller = new VehicleStatsObject();
using (var DB = DataContext.Get_DataContext)
{
var t = (from v in DB.VP_Historical_Vehicles
group v by new { v.make, v.model } into g
orderby g.Count() ascending
select new { make = g.Key.make, model = g.Key.model, count = g.Count() }).OrderByDescending(x => x.count).First();
BestSeller.Make = t.make;
BestSeller.Model = t.model;
BestSeller.CountValue = t.count;
}
return BestSeller;