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Convert SUM / CASE WHEN / GROUP BY SQL query into LINQ in C#

I have a table that has some value. I want to group by date month, My date field name is ApplicatonDate, and some enum values.
Here is a SQL query which I need to convert it into Linq:
SELECT
Count(he.ApplicationDate) AS Total,
MAX(he.ApplicationDate) AS ApplicationDate,
SUM(CASE WHEN he.Status=0 then 1 else 0 end )AS Last12MonthTotalPending,
SUM(CASE WHEN he.Status = 1 THEN 1 ELSE 0 END )AS Last12MonthTotalApproved,
SUM(CASE WHEN he.Status = 2 THEN 1 ELSE 0 END )AS Last12MonthTotalDenied
FROM dbo.Client_Heatings he
WHERE he.ApplicationDate >= DATEADD(Year,-1,GETDATE()) AND he.ApplicationDate <= GETDATE()
GROUP BY CAST(ApplicationDate AS DATE)
This is my LINQ. That is my WRONG LINQ.
var result = heatingList
.Where(r => r.Id == 123)
.GroupBy(r =>r.ApplicationDate )
.Select(grp => new HeatingApplicationSummaryDTO
{
Last12MonthTotalPending = grp.Sum( t => t.Status == 0 ? 1 : 0),
Last12MonthTotalApproved = grp.Sum( t => t.Status == 1 ? 1 : 0),
Last12MonthTotalDenied = grp.Sum( t => t.Status == 2 ? 1 : 0),
Total = grp.Sum(c => c.Status)
}).ToList();
I can't convert SQL query to LINQ query. I do not know how to convert and implement SUM/CASE section with Linq.
Thanks in advance

Try the following query:
var endDate = DateTime.Now;
var startDate = endDate.AddYears(-1);
var result = heatingList
.Where(r => r.ApplicationDate >= startDate && r.ApplicationDate <= endtDate)
.GroupBy(r => r.ApplicationDate.Date)
.Select(grp => new HeatingApplicationSummaryDTO
{
Total = grp.Count(),
ApplicationDate = grp.Max(t => t.ApplicationDate),
Last12MonthTotalPending = grp.Sum(t => t.Status == 0 ? 1 : 0),
Last12MonthTotalApproved = grp.Sum(t => t.Status == 1 ? 1 : 0),
Last12MonthTotalDenied = grp.Sum(t => t.Status == 2 ? 1 : 0),
}).ToList();

Get Values from single column based on condition

I have query and I can display values based on condition in SQL. But how can write C# LINQ query is my question.
SELECT Value
FROM db.table
WHERE xxId = 1 AND YYid = 2 AND IsActive = '1' AND IsDeleted = '0'
Result
NNNN
MMMM
TTTT
VVVV
LLLL
I need same query in LINQ C#
var results = db.table
.Select(a => a.xxid == xxid && a.yyid == id &&
a.IsActive && !a.IsDeleted).value;

var results = db.table
.Where(a => a.xxid == xxid && a.yyid == id && a.IsActive && !a.IsDeleted)
.Select(a => a.value)
.ToList();

Sum multiple column in LINQ

How can I reproduce this query using linq?
SELECT
SUM(SecondsSinceLastEvent) as AccessTime,
SUM (case when DownloadType = 0 then 1 end) FileDownloadCount,
SUM (case when DownloadType = 1 then 1 end) KortextDownloadCount,
SUM (case when Action = 'print' then 1 end) PrintCountFROM EReaderLogs WHERE PublishedContent_Id = XXX

In LINQ to Entities you need to first use GroupBy before using multiple aggregate functions. To sum all the elements in a column you can group by some static key so then a single group would be a whole table:
var query = context.EReaderLogs
.Where(e => e.PublishedContent_Id == someValue)
.GroupBy(a => 1, (k, g) =>
{
AccessTime = g.Sum(e => e.SecondsSinceLastEvent),
FileDownloadCount = g.Sum(e => e.DownloadType == 0 ? 1 : 0),
KortextDownloadCount = g.Sum(e => e.DownloadType == 1 ? 1 : 0),
PrintCount = g.Sum(e => e.Action == "print" ? 1 : 0)
});

Comparing SQL Date Time in Entity Framework by date parts

I have this query that was actually a view but I wanted to control the WHERE clause so I decided to tackle it by LINQ and EF6:
SELECT NULLIF(SUM([a].[REQUESTED_QTY]), 0) AS [Transaction],
NULLIF(SUM([a].[ITEM_TOTAL]), 0) AS [Income]
FROM [dbo].[BILL_INFO_DETAIL] AS [a]
INNER JOIN [dbo].[SERVICE_INFO] AS [b]
ON [a].[SERVICE_CODE] = [b].[SERVICE_CODE]
WHERE ([a].[INPUT_STATUS] = '1')
AND ([b].[SERVICE_CODE] IN ( 1610, 1611, 1612 ))
AND ([a].[PAY_MODE_ID] IN ( 1, 2 ))
AND (CONVERT(VARCHAR(2), a.STAMP_DATE, 101) IN ( '10', '11', '12' ))
AND (CONVERT(VARCHAR(4), a.STAMP_DATE, 102) IN ( '2017' ))
AND ([b].[FEE] > 1)
After a while of trial and error, I got this conversion:
public async Task<ViewGuessOnline> GetGuessOnline(int[] serviceCodes, byte[] payModes, string[] months, string year)
{
try
{
using (var context = new FinanceConnection())
{
var resultTemp = from a in
(from a in context.BILL_INFO_DETAILS
where
a.INPUT_STATUS == true &&
serviceCodes.Contains(a.SERVICE_INFO.SERVICE_CODE) &&
payModes.Contains(a.PAY_MODE_ID) &&
months.Contains(SqlFunctions.StringConvert(a.STAMP_DATE)) &&
(new[] {"2017"}).Contains(SqlFunctions.StringConvert(a.STAMP_DATE)) &&
a.SERVICE_INFO.FEE > 1
select new
{
a.REQUESTED_QTY,
a.ITEM_TOTAL,
Dummy = "x"
})
group a by new {a.Dummy}
into g
select new
{
Transaction = g.Sum(p => p.REQUESTED_QTY) == 0 ? (int?) null : (int) g.Sum(p => p.REQUESTED_QTY),
Income = g.Sum(p => p.ITEM_TOTAL) == 0 ? (decimal?) null : (decimal) g.Sum(p => p.ITEM_TOTAL)
};
// result = (await result.OrderByDescending(o => o.CustomerCode).ToListAsync()).AsQueryable();
}
Logger.Info($"{LayerName} -> {callerInfo.MethodName} -> Returning");
return result;
}
catch (Exception exp)
{
Logger.Error($"{LayerName} -> {callerInfo.MethodName} -> Exception [{exp.Message}]", exp);
throw;
}
}
I'm having an issue with the date part. In original SQL, the comparison of a Quarter 4 of 2107 is very easy. But I cannot find a proper inline linq conversion that translates to proper SQL.
Also, I had to use a dummy grouping even thoug there is not groups in the original SQL.

A bit more wall-baning and I was able to make this work:
from a in
(from a in db.BILL_INFO_DETAIL
where
a.INPUT_STATUS == true &&
(new int[] {1610, 1611, 1612 }).Contains(a.SERVICE_INFO.SERVICE_CODE) &&
(new int[] {1, 2 }).Contains(a.PAY_MODE_ID) &&
a.STAMP_DATE != null &&
(new int[] {10, 11, 12 }).Contains(a.STAMP_DATE.Value.Month) &&
a.STAMP_DATE.Value.Year == 2017 &&
a.SERVICE_INFO.FEE > 1
select new
{
a.REQUESTED_QTY,
a.ITEM_TOTAL,
Dummy = "x"
})
group a by new {a.Dummy}
into g
select new
{
Transaction = g.Sum(p => p.REQUESTED_QTY) == 0 ? (int?) null : (int) g.Sum(p => p.REQUESTED_QTY),
Income = g.Sum(p => p.ITEM_TOTAL) == 0 ? (decimal?) null : (decimal) g.Sum(p => p.ITEM_TOTAL)
}
I changed the method's parameter datatypes accordingly and this works now.

Converting Sql to Linq using group get wrong result

I have a query where I need to get the count of Commpliance and NonCompliance
Here is the SQL version I need this to convert to linq...
select ScheduleClause,
COUNT(case Compliance
when 1 then 1 end) Compliance,
Count(case Compliance
when 0 then 1 end) NonCompliance
from Compliance_RiskRegisterEntry cr
where cr.RiskRegisterTypeId = 1 and Auditor = 5508 and MONTH(AuditDate) = 10 and YEAR(AuditDate) = 2013
group by ScheduleClause
I try this linq query but I get different result
compliance
.GroupBy(x => new
{
x.ScheduleClause, x.Compliance
})
.Where(x => x.Key.Compliance == 1)
.Select(x => new RiskRegisterCompliancePerCategoryDto
{
ScheduleClause = x.Key.ScheduleClause,
Compliant = x.Key.Compliance == 1 ? 1 : 0,
NonCompliant = x.Key.Compliance == 0 ? 1 : 0,
GrandTotal = x.Count()
}).ToList();

It depends on your exact column definitions. Here I'm using
Create Table Compliance_RiskRegisterEntry (
ScheduleClause varchar(10),
AuditDate datetime not null,
RiskRegisterTypeID int not null,
Auditor Int,
Compliance bit not null
);
With this, the following Linq works:
compliance
.Where(p => p.RiskRegisterTypeID == 1 &&
p.Auditor == 5508 &&
p.AuditDate.Month == 10 &&
p.AuditDate.Year == 2013
)
.GroupBy(x => x.ScheduleClause)
.Select(x => new {
ScheduleClause = x.Key,
Compliant = x.Sum(y => y.Compliance ? 1 : 0),
NonCompliant = x.Sum(y => y.Compliance ? 0 : 1),
GrandTotal = x.Count()
});
Instead of x.Sum(...) you can use x.Count(y.Compliance), but the generated query for this looks much worse than using Sum

compliance
.Where(p=> p.RiskRegisterTypeId = 1 && p.Auditor = 5508 &&
SqlFunctions.DatePart("MM", p.AuditDate) = 10 &&
SqlFunctions.DatePart("yy", p.AuditDate) = 2013)
.GroupBy(x => x.ScheduleClause)
.Select(x => new RiskRegisterCompliancePerCategoryDto
{
ScheduleClause = x.Key.ScheduleClause,
Compliant = x.Key.Compliance == 1 ? 1 : 0,
NonCompliant = x.Key.Compliance == 0 ? 1 : 0,
GrandTotal = x.Count()
}).ToList();