convert SQL to LINQ or imporve my query please - c#

I am trying to convert sql to lambda or LINQ but can't simplified yet,
I managed to do it two different lambda but i want it a single query.
SQL query is this :
SELECT PamID, MAX (MaxAmount)
FROM RebateTable
GROUP BY PamID
so far this is working but is there any better way.
var t = from r in RebateList
group r by r.PamID;
var x = from y in t
select new RebateMaxClass
{
PamId = y.Key,
TotalSale = y.Max(s => s.MaxAmount)
};

You could use this form:
RebateTable.GroupBy(r=>r.PamId).Select(s=>new RebateMaxClass
{
PamId = s.Key,
TotalSale = s.Max(y => y.MaxAmount)
};

The query look good. You could form a single query like this:
var t = from r in RebateList
group r by r.PamId into y
select new
{
PamId = y.Key,
TotalSale = y.Max(s => s.MaxAmount)
};
But this is not faster. The Query is extended and will ont be executed until is has to.
An alternative is forming the "new LinQ-Style":
var t2 = RebateList.GroupBy(g => g.PamId) // Do a Grouping
var t3 = t2.Select(s => new { PamId = s.Key, TotalSale = s.Max(m => m.MaxAmount) });

Related

LINQ Query with GroupBy, MAX and Count

What could be the LINQ query for this SQL?
SELECT PartId, BSId,
COUNT(PartId), MAX(EffectiveDateUtc)
FROM PartCostConfig (NOLOCK)
GROUP BY PartId, BSId
HAVING COUNT(PartId) > 1
I am actually grouping by two columns and trying to retrieve max EffectiveDateUtc for each part.
This is what I could write. Stuck up on pulling the top record based on the date.
Also not sure, if this is a optimal one.
//Get all the parts which have more than ONE active record with the pat
//effective date and for the same BSId
var filters = (from p in configs
?.GroupBy(w => new
{
w.PartId,
w.BSId
})
?.Select(g => new
{
PartId = g.Key.PartId,
BSId = g.Key.BSId,
Count = g.Count()
})
?.Where(y => y.Count > 1)
select p)
?.Distinct()?.ToList();
var filteredData = (from p in configs
join f in filters on p.PartId equals f.PartId
select new Config
{
Id = p.Id,
PartId = p.PartId,
BSId = p.BSId,
//EffectiveDateUtc = MAX(??)
}).OrderByDescending(x => x.EffectiveDateUtc).GroupBy(g => new { g.PartId, g.BSId }).ToList();
NOTE: I need the top record (based on date) for each part. Was trying to see if I can avoid for loop.
The equivalent query would be:
var query =
from p in db.PartCostConfig
group p by new { p.PartId, p.BSId } into g
let count = g.Count()
where count > 1
select new
{
g.Key.PartId,
g.Key.BSId,
Count = count,
EffectiveDate = g.Max(x => x.EffectiveDateUtc),
};
If I understand well, you are trying to achieve something like this:
var query=configs.GroupBy(w => new{ w.PartId, w.BSId})
.Where(g=>g.Count()>1)
.Select(g=>new
{
g.Key.PartId,
g.Key.BSId,
Count = g.Count(),
EffectiveDate = g.Max(x => x.EffectiveDateUtc)
});

Grouping and Sum some field with Sub query in LINQ

I'm trying to convert my sql query to linq, i confused about sum and grouping,
this is my query
SELECT
produk.supplier,
SUM(transaksi.jumlah_transaksi),
SUM(transaksi.nominal_transaksi),
operasional.nominal
FROM
transaksi INNER JOIN produk ON transaksi.id_produk = produk.id_produk
LEFT JOIN
(SELECT
operasional.id_supplier,
SUM(nominal) AS nominal
FROM
operasional) operasional
ON operasional.id_supplier = produk.id_supplier
GROUP BY produk.supplier
output should be
like this
Progress
i am just trying with linq query like this without grouping
var result = from t in db.transaksi
join p in db.produk on t.id_produk equals p.id_produk
from op in
(
from o in db.operasional
select new
{
id_supplier = o.id_supplier,
nominal = o.nominal
}
).Where(o => o.id_supplier == p.id_supplier).DefaultIfEmpty()
select new
{
nama_supplier = p.supplier,
jumlah_transaksi = t.jumlah_transaksi,
nominal_transaksi = t.nominal_transaksi,
biaya_operasional = op.nominal
};
and result query from my linq still like this
SELECT
`p`.`supplier`,
`t`.`jumlah_transaksi`,
`t`.`nominal_transaksi`,
`t1`.`nominal`
FROM
`transaksi` `t`
INNER JOIN `produk` `p`
ON `t`.`id_produk` = `p`.`id_produk`
LEFT JOIN `operasional` `t1`
ON `t1`.`id_supplier` = `p`.`id_supplier`
Solved
and this is my full linq
var result = from t in db.transaksi
join p in db.produk on t.id_produk equals p.id_produk
from op in
(
from o in db.operasional
group o by o.id_supplier into g
select new
{
id_supplier = g.First().id_supplier,
nominal = g.Sum(o => o.nominal)
}
).Where(o => o.id_supplier == p.id_supplier).DefaultIfEmpty()
select new
{
nama_supplier = p.supplier,
jumlah_transaksi = t.jumlah_transaksi,
nominal_transaksi = t.nominal_transaksi,
biaya_operasional = op.nominal
};
var grouped = result
.GroupBy(x => x.nama_supplier)
.Select(x => new
{
nama_supplier = x.Key,
jumlah_transaksi = x.Sum(s => s.jumlah_transaksi),
nominal_transaksi = x.Sum(s => s.nominal_transaksi),
biaya_operasional = x.Select(s => s.biaya_operasional).First()
});
Try to use GroupBy (in following code result is your query from code above):
var grouped = result
.GroupBy(x => x.nama_supplier)
.Select(x => new {
nama_supplier = x.Key,
sum1 = x.Sum(s => s.jumlah_transaksi),
sum1 = x.Sum(s => s.nominal_transaksi),
nominal = x.Select(s => s.biaya_operasional).First()
})
Code is not checked so use it just as idea.

Selecting multiple columns from each row and removing duplicates

Say I have a table with the following structure:
- Id
- Phone1
- Phone2
- Address
This table has multiple records.
What's the best way, using linq to SQL, of selecting all the phone numbers (from columns "Phone1" and "Phone2") in each row, and also removing repeated values.
I've tried something like but I can only get one column (Phone1) in each row:
var listOfResults = (from x in table
select x.Select(z => z.Phone1).Distinct()
).ToList();
Many thanks!
You can do this:
var listOfResults = (from x in table
select new
{
Phone1 = x.Phone1,
Phone2 = x.Phone2
}).Distinct();
or use groupby:
var listOfResults = (from x in table
group x by new { x.Phone1,x.Phone2 } into g
select new
{
Phone1 = g.Key.Phone1,
Phone2 = g.Key.Phone2
});
UPDATE:
var listOfResults = (from x in table
select new[]
{
new { Phone = x.Phone1 },
new { Phone = x.Phone2}
}).SelectMany(x=>x).Distinct();
var listOfPhone1 = (from x in table select x.Select(z => z.Phone1);
var listOfPhone2 = (from x in table select x.Select(z => z.Phone2);
var listOfResults = (listOfPhone1.AddRange(listOfPhone2)).Distinct();
You could have a look at the MoreLinq library found here. They have a function called DistinctBy which should solve your problem.
I don't know if this works with Linq-to-SQL, but with Linq-to-Object I would do it this way:
var unified = addresses.SelectMany(Row => new[] { new { Row, Phone = Row.Phone1 }, new { Row, Phone = Row.Phone2 } })
.Distinct(entry => entry.Phone)
.Select(entry => entry.Row);

convert sql to linq with two tables

select ind.desc,ind.number
from int_goals_df idd, goals_df ind
where idd.dld_number = 123456
and ind.number = idd.ind_number
and ind.categorie = 2
order by follownumber
I'm having a hard time translating this to linq since it is using two tables.
I've currently solved this now imperatively with a foreach loop but not happy with it..
I'm trying to get a list of goals_df that matches with a list of int_goals_df.
Any tips would be greatly appreciated ! Thank you !
EDIT - here is the code I'm using:
//get current GoalDefinitions by selected Goal
var currentGoalDefinition = MyAppAppContext.MyAppAppContextInstance.MyAppContext.GoalDefinitions.FirstOrDefault(
d => d.DLD_GoalDFID == interv.Goal.DLD_GoalenDFID);
// get current intervGoalDefinitions by GoalDefinition
var currentintervGoalDefinitions = MyAppAppContext.MyAppAppContextInstance.MyAppContext.intervGoalDefinitions.Where(
idd => idd.DLD_GoalDFID == currentGoalDefinition.DLD_GoalDFID).OrderBy(idd => idd.IDD_VolgNummer);
intervDefinitionCollection = new ObservableCollection<intervDefinition>(MyAppAppContext.MyAppAppContextInstance.MyAppContext.intervDefinitions.Where(i => i.IND_Categorie == intCategorie));
// filter intervGoalDefinitions by intervDefinitions
var intervDefinitionCollectionTemp = new ObservableCollection<intervDefinition>();
foreach (var currentintervGoalDefinity in currentintervGoalDefinitions)
{
var foundintervGoalDefinitySorted = intervDefinitionCollection.FirstOrDefault(
i => i.IND_intervDFID == currentintervGoalDefinity.IND_intervDFID);
if (foundintervGoalDefinitySorted != null)
intervDefinitionCollectionTemp.Add(foundintervGoalDefinitySorted);
}
intervDefinitionCollection = intervDefinitionCollectionTemp;
assuming NHibernate as ORM and int_goal is a subclass of goal
var results = from idd in session.Query<IntGoals>()
where idd.DlDNumber = 123456 && idd.Category.Id == 2
orderby idd.FollowNumber
select new { idd.Description, idd.Number };
context.int_goals_df.Join(context.goals_df, x => x.ind_number, x => x.number,
(x, y) => new
{
idd = x,
ind = y
})
.Where(x => x.idd.dld_number = 123456 && x.ind.categorie = 2)
.OrderBy(x => x.idd.follownumber)
.Select(x => new
{
x.ind.desc,
x.ind.number
});
quick go - think you need the join
var results = from idd in session.Query<int_goals_df>()
join ind in session.Query<goals_df>()
on idd.ind_number equals ind.ind_number
where idd.DlDNumber = 123456 && idd.Category.Id == 2
orderby idd.FollowNumber
select new { idd.Description, idd.Number };
I tend to use the sql syntax without implicit joins
/*Fields*/
SELECT ind.desc, ind.number
/*Tables*/
FROM int_goals_df idd
INNER JOIN goals_df ind
ON ind.number = idd.ind_number
/*Conditions*/
WHERE idd.dld_number = 123456
AND ind.categorie = 2
/*Order/Grouping*/
ORDER BY follownumber
You can see from Chris's answer this translates more easily to linq.

Converting SQL to Linq with groupby, sum and count

I would like to do a group by and on that a sum and a count. I don't seem to be able to create the solution in linq. How can I convert my query to linq?
SELECT HistoricalBillingProductGroup,
COUNT(*),
BillingPeriod,
SUM(TotalMonthlyChargesOtcAndMrc)
FROM [x].[dbo].[tblReport]
group by BillingPeriod, HistoricalBillingProductGroup
order by BillingPeriod
This is what I got sofar in Linq
var result =
context.Reports.GroupBy(x => new {x.BillingPeriod, x.HistoricalBillingProductGroup})
.Select(x => new StatisticsReportLine
{
HistoricalBillingGroup = x.FirstOrDefault().HistoricalBillingProductGroup,
BillingPeriod = x.FirstOrDefault().BillingPeriod,
CountOfRows = x.Count(),
SumOfAmount = x.Sum(p => p.TotalMonthlyChargesOtcAndMrc) ?? 0
})
.ToString();
The query I get from this is enormous and takes a very long time to load. In SQL its a matter of milliseconds. I hardly doubt this is the solution.
I believe the calls to x.FirstOrDefault() are the source of your problem. Each one of these will result in a very costly inner query inside the SELECT clause of the generated SQL.
Try using the Key property of the IGrouping<T> instead :
var result = context.Reports
.GroupBy(x => new {x.BillingPeriod, x.HistoricalBillingProductGroup})
.OrderBy(x => x.Key.BillingPeriod)
.Select(x => new StatisticsReportLine
{
HistoricalBillingProductGroup = x.Key.HistoricalBillingProductGroup,
BillingPeriod = x.Key.BillingPeriod,
CountOfRows = x.Count(),
SumOfAmount = x.Sum(p => p.TotalMonthlyChargesOtcAndMrc) ?? 0
});
Or if you prefer query syntax:
var result =
(from r in context.Reports
group r by new { r.BillingPeriod, r.HistoricalBillingProductGroup } into g
orderby g.Key.BillingPeriod
select new StatisticsReportLine
{
HistoricalBillingProductGroup = g.Key.HistoricalBillingProductGroup,
BillingPeriod = g.Key.BillingPeriod,
CountOfRows = g.Count(),
SumOfAmount = x.Sum(p => p.TotalMonthlyChargesOtcAndMrc) ?? 0
});
You could try this one:
var result = context.Reports
.GroupBy(x => new {x.BillingPeriod, x.HistoricalBillingProductGroup})
.Select(x => new StatisticsReportLine
{
HistoricalBillingGroup = x.Key.HistoricalBillingProductGroup,
BillingPeriod = x.Key.BillingPeriod,
CountOfRows = x.Count(),
SumOfAmount = x.Sum(p => p.TotalMonthlyChargesOtcAndMrc) ?? 0
}).ToString();
In the above query you make a group by on two properties, BillingPeriod and HistoricalBillingProductGroup. So in each group that will be created, you will have a key, that will be consisted by these two properties.

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