getting the MAX() value using LINQ [duplicate] - c#

This question already has answers here:
C# Using LINQ to select max ID of row
(6 answers)
Closed 8 years ago.
I'm trying to select the max value of BreadCrumbID from the table tbBreadCrumb when I return multiple rows. Right now I join the tabel tbBreadCrumb to the table tbProjects. If there are multiple entries in tbBreadCrumb I return the multiple entries. But I only want to select the row in tbBreadCrumb that has the highest BreadCrumbID.
Here's my code:
using (dbPSREntities5 myEntities = new dbPSREntities5())
{
var allDepartments = (from tbProject in myEntities.tbProjects
from tbBreadCrumb in myEntities.tbBreadCrumbs.Where(x => x.ProjectID == tbProject.ProjectID) <--- I want to put some sort of Max() function here where it will only slect the row with the max BreadCrumID in the table tbBreadCrumb
from refBreadCrumb in myEntities.refBreadCrumbs.Where(x => x.refBreadCrumbID == tbBreadCrumb.StatusID)
// select new anon type
select new
{
ProjectID = tbProject.ProjectID,
Status = refBreadCrumb.BreadCrumbValue,
DateSubmitted = tbBreadCrumb.CreateDateTime,
refDepartmentID = tbProject.refDepartmentID,
ProjectContactFullName = tbProject.ProjectContactFirstName + " " + tbProject.ProjectContactLastName,
ProjectWorkType = tbProject.ProjectWorkType,
});
projectsListView.DataSource = allDepartments;
projectsListView.DataBind();
}

You can try this,first get the Maximum BreadCrumbID Id.Then use it with where in the second query :
var breadId = myEntities.tbBreadCrumbs.Max(x => x.BreadCrumbID);
var allDepartments = (from tbProject in myEntities.tbProjects
from tbBreadCrumb in myEntities.tbBreadCrumbs.Where(x => x.ProjectID == tbProject.ProjectID && x.BreadCrumbID == breadId)
from refBreadCrumb in myEntities.refBreadCrumbs.Where(x => x.refBreadCrumbID == tbBreadCrumb.StatusID)
// select new anon type
select new
{
ProjectID = tbProject.ProjectID,
Status = refBreadCrumb.BreadCrumbValue,
DateSubmitted = tbBreadCrumb.CreateDateTime,
refDepartmentID = tbProject.refDepartmentID,
ProjectContactFullName = tbProject.ProjectContactFirstName + " " + tbProject.ProjectContactLastName,
ProjectWorkType = tbProject.ProjectWorkType,
});
Update:
var allDepartments = (from tbProject in myEntities.tbProjects
from tbBreadCrumb in myEntities.tbBreadCrumbs.Where(x => x.ProjectID == tbProject.ProjectID && x.BreadCrumbID == myEntities.tbBreadCrumbs.Where(y => y.ProjectID == tbProject.ProjectID).Max(y => y.BreadCrumbID))
from refBreadCrumb in myEntities.refBreadCrumbs.Where(x => x.refBreadCrumbID == tbBreadCrumb.StatusID)
// select new anon type
select new
{
ProjectID = tbProject.ProjectID,
Status = refBreadCrumb.BreadCrumbValue,
DateSubmitted = tbBreadCrumb.CreateDateTime,
refDepartmentID = tbProject.refDepartmentID,
ProjectContactFullName = tbProject.ProjectContactFirstName + " " + tbProject.ProjectContactLastName,
ProjectWorkType = tbProject.ProjectWorkType,
});

Related

Why Same where clause need to write multiple times in a Linq Query for following SQL

What will be the proper linq syntax of below SQL Query ?
select a.id, a.AppointmentStatusID, ad.ID as DetailID
from [dbo].[Appointment] a, [dbo].[AppointmentDetail] ad
where a.[ID] = ad.[AppointmentID]
and a.CompanyID = 'a3dea87a-804e-4115-98cf-472988cf1678'
and a.LocationID = '3165caca-2a48-46f0-bbed-578cff29167t'
and ad.AppDateFrom <= {ts '2017-11-14 23:59:31'}
and ad.AppDateTo >= {ts '2017-11-14 00:00:00'}
and ad.[ApprovalStatusID] = 2
Problem I faced:
I required to filter Where Condition two times 1st at the time within the join & 2nd time during the object.Select expression, please check bellow
var results = (from a in appointments
join ad in _appointmentDetailRepository.GetAll() on a.ID equals ad.AppointmentID
where ad.ApprovalStatusID == 2
&& DbFunctions.TruncateTime(ad.AppDateFrom) <= DbFunctions.TruncateTime(viewmodel.AppointmentDate)
&& DbFunctions.TruncateTime(ad.AppDateTo) >= DbFunctions.TruncateTime(viewmodel.AppointmentDate)
orderby a.ID
select new Appointment
{
ID = a.ID,
CompanyID = a.CompanyID,
LocationID = a.LocationID,
AppointmentDetail = a.AppointmentDetail.Select(ad => new AppointmentDetail
{
ID = ad.ID,
AppDateFrom = ad.AppDateFrom,
AppDateTo = ad.AppDateTo,
AppointmentStatusID = ad.AppointmentStatusID,
}).Where(ad=> ad.ApprovalStatusID == 2
&& DbFunctions.TruncateTime(ad.AppDateFrom) <= DbFunctions.TruncateTime(viewmodel.AppointmentDate)
&& DbFunctions.TruncateTime(ad.AppDateTo) >= DbFunctions.TruncateTime(viewmodel.AppointmentDate)).ToList()
}).GroupBy(x => x.ID).Select(x => x.DefaultIfEmpty().FirstOrDefault());
Query : Why I required to write Where clause 2 times ?
Required Result
An Appointment Object --> Containing ICollection<AppoinmentDetails> if Details.Where Condition == True
From what I see (without knowing the model you have), it looks like you should use the already joined and filtered Details from ad instead of looking it up again from the Property a.AppointmentDetail...
Untested:
select new Appointment
{
ID = a.ID,
CompanyID = a.CompanyID,
LocationID = a.LocationID,
AppointmentDetail = ad.ToList(), // <-- don't you think?
...
}
For the given SQL query
select a.id, a.AppointmentStatusID, ad.ID as DetailID
from [dbo].[Appointment] a, [dbo].[AppointmentDetail] ad
where a.[ID] = ad.[AppointmentID]
and a.CompanyID = 'a3dea87a-804e-4115-98cf-472988cf1678'
and a.LocationID = '3165caca-2a48-46f0-bbed-578cff29167t'
and ad.AppDateFrom <= {ts '2017-11-14 23:59:31'}
and ad.AppDateTo >= {ts '2017-11-14 00:00:00'}
and ad.[ApprovalStatusID] = 2
LINQ query can be written as
var results = (from a in appointments
join ad in appointmentDetails on a.ID equals ad.AppointmentID
where ad.ApprovalStatusID == 2
&& a.CompanyID == "a3dea87a-804e-4115-98cf-472988cf1678"
&& a.LocationID == "3165caca-2a48-46f0-bbed-578cff29167t"
&& ad.AppDateFrom.Date <= viewmodel.AppointmentDate.Date
&& ad.AppDateTo.Date >= viewmodel.AppointmentDate.Date
select new
{
ID = a.ID,
AppointmentStatusID = a.AppointmentStatusID,
DetailID = ad.ID
}).ToList();
You can also write it like
var results = appointmentDetails
.Where(ad => ad.AppDateFrom.Date <= viewmodel.AppointmentDate.Date
&& ad.AppDateTo.Date >= viewmodel.AppointmentDate.Date
&& ad.ApprovalStatusID == 2
&& ad.Appointment.CompanyID == "a3dea87a-804e-4115-98cf-472988cf1678"
&& ad.Appointment.LocationID == "3165caca-2a48-46f0-bbed-578cff29167t")
.Select(ad =>
new
{
ID = ad.Appointment.ID,
AppointmentStatusID = ad.Appointment.AppointmentStatusID,
DetailID = ad.ID
})
.ToList()
As per the updated question, to get the the Appointment object with a collection of AppointmentDetails, please try this query
var results = appointmentDetails
.Where(ad => ad.AppDateFrom.Date <= viewmodel.AppointmentDate.Date
&& ad.AppDateTo.Date >= viewmodel.AppointmentDate.Date
&& ad.ApprovalStatusID == 2
&& ad.Appointment.CompanyID == "a3dea87a-804e-4115-98cf-472988cf1678"
&& ad.Appointment.LocationID == "3165caca-2a48-46f0-bbed-578cff29167t")
.Select(ad =>
new
{
ID = ad.Appointment.ID,
AppointmentStatusID = ad.Appointment.AppointmentStatusID,
Detail = ad
})
.AsEnumerable()
.GroupBy(a => new { a.ID, a.AppointmentStatusID })
.Select(a => new Appointment
{
ID = a.Key.ID,
AppointmentStatusID = a.Key.AppointmentStatusID,
AppointmentDetails = a.Select(d => d.Detail).ToList()
})
.ToList();

Yet another “A query body must end with a select clause or a group clause”

This query does work, but I am trying to combine the two steps into one query.
var query1 = from b in db.GetTable<Boats>()
from o in db.GetTable<Offices>()
from u in db.GetTable<Users>()
.Where
(u =>
u.UserId == b.Handling_broker &&
o.Office == b.Handling_office &&
b.Status == 2 &&
officesToInclude.Contains(b.Handling_office)
)
select new
{
hOffice = o.Name,
bName = u.Name
};
var query2 = query1.GroupBy(t => new { office = t.hOffice, name = t.bName })
.Select(g => new { Office = g.Key.office, Name = g.Key.name, Count = g.Count() });
If I try to combine the two queries using the following query it gives me the “A query body must end with a select clause or a group clause” error.
var query1 = from b in db.GetTable<Boats>()
from o in db.GetTable<Offices>()
from u in db.GetTable<Users>()
.Where
(u =>
u.UserId == b.Handling_broker &&
o.Office == b.Handling_office &&
b.Status == 2 &&
officesToInclude.Contains(b.Handling_office)
)
.GroupBy(t => new { office = t.Office, name = t.Name })
.Select(g => new { Office = g.Key.office, Name = g.Key.name, Count = g.Count() });
I think I have to add a select something, but I can't figure out what.
Can anyone please help?
Your query must contain a select clause. The .Where(...).GroupBy(...).Select(...) are only on the db.GetTable<Users>(). Something like:
var query1 = from b in db.GetTable<Boats>()
from o in db.GetTable<Offices>()
from u in db.GetTable<Users>().Where(u => u.UserId == b.Handling_broker &&
o.Office == b.Handling_office &&
b.Status == 2 &&
officesToInclude.Contains(b.Handling_office))
.GroupBy(t => new { office = t.Office, name = t.Name })
.Select(g => new { Office = g.Key.office, Name = g.Key.name, Count = g.Count() })
select new { /* Desired properties */};
But I think you are looking for something like:
var result = from b in db.GetTable<Boats>()
from o in db.GetTable<Offices>()
from u in db.GetTable<Users>()
where u.UserId == b.Handling_broker &&
o.Office == b.Handling_office &&
b.Status == 2 &&
officesToInclude.Contains(b.Handling_office))
group 1 by new { t.Office, t.Name } into g
select new { Office = g.Key.Office, Name = g.Key.Name, Count = g.Count() };

How to use linq result input sql where in

I have a linq script
var ID = (from item in ConflictDatas.AsEnumerable()
group item by new
{
ID = item.Field<string>("ID"),
DesignArticle = item.Field<string>("DesignArticle"),
DesignNo = item.Field<string>("DesignNo"),
PatternCode = item.Field<string>("PatternCode")
} into g
where g.Count() >= 2
select new
{
g.Key.ID
}).ToList();
I want to put this result into a sql commnad.
I try:
string sqlwhere;
sqlwhere = string.Join(",", ID);
tsql = #"
Insert ConflictDesignArticle
Select * from ReadyworkData where ID in (" + sqlwhere + #") ";
After compile:
Insert ConflictDesignArticle
Select * from ReadyworkData where ID in ({ ID = SPSOS17040113 },{ ID =
SPSOS17040115 },{ ID = SPSOS17040114 })
How to modify my code. Thanks.
Thank you for Lei Yang help
var ID = (from item in ConflictDatas.AsEnumerable()
group item by new
{
ID = item.Field<string>("ID"),
DesignArticle = item.Field<string>("DesignArticle"),
DesignNo = item.Field<string>("DesignNo"),
PatternCode = item.Field<string>("PatternCode")
} into g
where g.Count() >= 2
select new
{
g.Key.ID
}).Select(x => x.ID).ToList();

LINQ sum not performed when values are identical

I need to sum elements of same type starting from 2 LINQ queries.
Below is my code:
var query1 = from d in _contextProvider.Context.Documents
where d.TransportId == transportId
group d by d.Type
into dg
select new { DocumentType = dg.Key.ToString(), DocumentCount = dg.Count() };
var query2 = from n in _contextProvider.Context.NotificationDocuments
where n.TransportId == transportId
group n by n.TransportId
into nd
select new { DocumentType = "Notification", DocumentCount = nd.Count() };
var query_collapsed = query1.Union(query2)
.GroupBy(p => new { DocumentType = p.DocumentType })
.Select(g => new DocumentCounters() { DocumentType = g.Key.DocumentType, DocumentCount = g.Sum(p => p.DocumentCount) });
Example: below let's analyse values for DocumentType equals to Notification.
Values of query1:
Values of query2:
The collapsed query :
That's correct: 1 + 2 = 3
The problem: I noticed that whenever the count for Notification in query1 is equals to the count for Notification in query2, then the sum is not performed.
Example:
2 + 2 = 2
or
3 + 3 = 3
Any ideas ?
LINQ Union will remove duplicate entries. If you want to merge the two sequences you can use Concat like so:
var query_collapsed = query1.Concat(query2)
.GroupBy(p => new { DocumentType = p.DocumentType })
.Select(g => new DocumentCounters() { DocumentType = g.Key.DocumentType, DocumentCount = g.Sum(p => p.DocumentCount) });

LINQ pivot top 5 rows to columns

The desired output is a set of rows containing details about a physician and the top 5 procedures they performed (by volume) that are not in our benchmarking tables - with a minimum of one per month. Even with my limited LINQ experience, I have managed to get this working, but the performance in abysmal. In the spirit of becoming better at LINQ, I thought I'd see if there was a better way to approach this (besides coding in SQL).
Here is the entire method, although I believe it is the final statement (var report =) that deserves the most attention.
//Get the Providers for the selected AccessLevel & Report Period
var providerRiskLevels = GetProviderRiskLevelForAccessLevel(userAccessLevelId, reportPeriodId, providerNamePiece);
short benchmarkYear = (
from rp in db.ReportPeriods
where rp.ReportPeriodId == reportPeriodId
select rp.BenchmarkDataYear
).FirstOrDefault();
byte Duration = (
from rp in db.ReportPeriods
where rp.ReportPeriodId == reportPeriodId
select rp.Duration
).FirstOrDefault();
//Summarize counts by procedure code (ignoring modifiers)
var codeCounts =
from pp in db.ProviderProductions
//332 - restrict to valid codes
join pc in db.ProcedureCodes on pp.ProcedureCode equals pc.ProcedureCode1
where pp.ReportPeriodId == reportPeriodId
//show deleted codes as potential issue
&& pc.TerminatedDate == null
&& (codeFilter == null || pp.ProcedureCode == codeFilter)
join pc in db.PspsProcedures
on new { col1 = pp.ProcedureCode, col2 = benchmarkYear } equals new { col1 = pc.ProcedureCode, col2 = pc.Year } into left
from l_d in left.DefaultIfEmpty()
where l_d == null
group pp by
new { pp.ProviderId, pp.ProcedureCode }
into g
orderby g.Key.ProviderId, g.Sum(x => x.Volume) descending
where g.Sum(x => x.Volume) > Duration
select new NewCodesEntity
{
ProviderId = g.Key.ProviderId,
ProcedureCode = g.Key.ProcedureCode,
Volume = g.Sum(x => x.Volume)
};
//Get top 5 procedures performed by provider
var newCodes =
from cc in codeCounts
group cc by
new { cc.ProviderId }
into g
select new ProviderNewCodesEntity
{
ProviderId = g.Key.ProviderId,
Codes = g.OrderByDescending(x => x.Volume).Take(5).ToList()
};
//Build the report
var report =
from pr in providerRiskLevels
join nc in newCodes on pr.Provider.ProviderId equals nc.ProviderId
where pr.RiskCategoryId == RiskCategoryIds.VisibleRisk
&& (filterRiskLevelNums.Contains(pr.RiskLevelNum))
&& (filterSpecialtyId == 0 || pr.Provider.Specialty.SpecialtyId == filterSpecialtyId)
select new ProbeAuditEntity
{
ProviderId = pr.Provider.ProviderId,
ProviderName = pr.Provider.Name,
ProviderCode = pr.Provider.ProviderCode,
SpecialtyName = pr.Provider.Specialty.Name,
SpecialtyCode = pr.Provider.Specialty.SpecialtyCode,
VisibleRisk = pr.RiskScore,
NewCode1 = nc.Codes.OrderByDescending(c => c.Volume).FirstOrDefault().ProcedureCode,
NewCode2 = nc.Codes.OrderByDescending(c => c.Volume).Skip(1).FirstOrDefault().ProcedureCode,
NewCode3 = nc.Codes.OrderByDescending(c => c.Volume).Skip(2).FirstOrDefault().ProcedureCode,
NewCode4 = nc.Codes.OrderByDescending(c => c.Volume).Skip(3).FirstOrDefault().ProcedureCode,
NewCode5 = nc.Codes.OrderByDescending(c => c.Volume).Skip(4).FirstOrDefault().ProcedureCode
};
return report;
I appreciate your suggestions.
Give this a try for the report:
//Build the report
var report =
(from pr in providerRiskLevels
join nc in newCodes on pr.Provider.ProviderId equals nc.ProviderId
where pr.RiskCategoryId == RiskCategoryIds.VisibleRisk
&& filterRiskLevelNums.Contains(pr.RiskLevelNum)
&& (filterSpecialtyId == 0
|| pr.Provider.Specialty.SpecialtyId == filterSpecialtyId)
select new
{
RiskLevel = pr,
NewCodes = nc.Codes.OrderByDescending(c => c.Volumn).Select(c => c.ProcedureCode).Take(5)
})
.AsEnumerable()
.Select(x => new ProbeAuditEntity
{
ProviderId = x.RiskLevel.Provider.ProviderId,
ProviderName = x.RiskLevel.Provider.Name,
ProviderCode = x.RiskLevel.Provider.ProviderCode,
SpecialtyName = x.RiskLevel.Provider.Specialty.Name,
SpecialtyCode = x.RiskLevel.Provider.Specialty.SpecialtyCode,
VisibleRisk = x.RiskLevel.RiskScore,
NewCodes = x.NewCodes.Concat(Enumerable.Repeat(<DefaultProcedureCodeHere>, 5)).Take(5)
});
Or, if ProbeAuditEntity is a class you could do this:
//Build the report
var report =
(from pr in providerRiskLevels
join nc in newCodes on pr.Provider.ProviderId equals nc.ProviderId
where pr.RiskCategoryId == RiskCategoryIds.VisibleRisk
&& filterRiskLevelNums.Contains(pr.RiskLevelNum)
&& (filterSpecialtyId == 0
|| pr.Provider.Specialty.SpecialtyId == filterSpecialtyId)
select new ProbeAuditEntity
{
ProviderId = x.RiskLevel.Provider.ProviderId,
ProviderName = x.RiskLevel.Provider.Name,
ProviderCode = x.RiskLevel.Provider.ProviderCode,
SpecialtyName = x.RiskLevel.Provider.Specialty.Name,
SpecialtyCode = x.RiskLevel.Provider.Specialty.SpecialtyCode,
VisibleRisk = x.RiskLevel.RiskScore,
NewCodes = nc.Codes.OrderByDescending(c => c.Volumn).Select(c => c.ProcedureCode).Take(5)
})
.ToList();
report
.ForEach(x => x.NewCodes = x.NewCodes.Concat(Enumerable.Repeat(<DefaultProcedureCodeHere>, 5)).Take(5);

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