Develop Reference

Problem adding a List inside a List on C# ADO.NET

I am trying to add a List inside a new List using C# and I get the following error:
System.NotSupportedException: 'A type that implements IEnumerable 'System.Collections.Generic.List`1
I tried a few methods to implement it but it didn't go trough.
This is what I have done:
public List<ExtendEmp> GetEmpDatas()
{
var result2 = from emp in db.employees
join dep in db.departments on emp.departmentID equals dep.ID
orderby emp.ID
select new ExtendEmp
{
ID = emp.ID,
fname = emp.fname,
lname = emp.lname,
startWorkYear = emp.startWorkYear,
name = dep.name,
manager = dep.manager,
ExtendShiftz = new List<ExtendShft>()
};
return result2.ToList();
}
The specific list I'm trying to add is ExtendShiftz which is initialised here:
public List<ExtendShft> GetShftDatas()
{
var result3 = from emp in db.employees
join emps in db.employee_shift on emp.ID equals emps.employeeid
join shft in db.shifts on emps.shiftid equals shft.ID
select new ExtendShft
{
ID = shft.ID,
employeeid = emps.employeeid,
fname = emp.fname,
lname = emp.lname,
shiftid = emps.shiftid,
date = shft.date,
startTime = shft.startTime,
endTime = shft.endTime
};
return result3.ToList();
}
and of course i added it inside my model that way:
public ExtendEmp()
{
ExtendShiftz = new List<ExtendShft>();
}
public List<ExtendShft> ExtendShiftz { get; set; }
If you guys have any idea what i am doing wrong there i'd be happy to read.

How to add the content of a combobox in a database

I want to add the content of the combobbox into my database, but it doesn't work. The content of my combobox is from the table 'Categories' who's joined with the table 'Products'. I've tried many things I have errors of conversion :
Here's my code :
Product p = new Product();
p.ProductName = txtNom.Text.Trim();
p.ProductDescription = txtDesc.Text.Trim();
p.ProductQuantityUsed = Convert.ToInt32(numQteUsed.Value);
p.ProductQuantityNew = Convert.ToInt32(numQteNew.Value);
p.CategoryID = cboCat.SelectedText.ToString();
db.Products.Add(p);
db.SaveChanges();
//Combobox
public void FillCbCategories()
{
SamsonEntities db = new SamsonEntities();
cboCat.Items.Clear();
var listCat = (from cats in db.Categories
select new CategoryDisplay()
{
CategoryID = cats.CategoryID,
CategoryName = cats.CategoryName
}).ToList();
for(var i=0;i<listCat.Count;i++)
{
cboCat.Items.Add(listCat[i]);
}
}

Judging by your comments, your combobox is not binded correctly to data you send to it.
You could try setting ValueMember and DisplayMember:
cboCat.ValueMember = "CategoryID";
cboCat.DisplayMember = "CategoryName";
in your method, like this:
public void FillCbCategories()
{
SamsonEntities db = new SamsonEntities();
cboCat.Items.Clear();
var listCat = (from cats in db.Categories
select new CategoryDisplay()
{
CategoryID = cats.CategoryID,
CategoryName = cats.CategoryName
}).ToList();
for(var i=0;i<listCat.Count;i++)
{
cboCat.Items.Add(listCat[i]);
}
cboCat.ValueMember = "CategoryID";
cboCat.DisplayMember = "CategoryName";
}

The cast to value type 'System.Int32' failed because the materialized value is null.

I'm trying to return a list of results, however. Whenever there are no results, I receive the error message which I have posted above. However, it's strange because whenever I add the variable q instead of the return, it just returns no results instead and is fine with this. I would prefer to do it the way which I am currently doing it right now, does anybody know what is wrong with the query? Whenever I run it in LINQPad it works completely fine.
public IQueryable<ClaimNumberReport> GetClaimsByClaimNumber(int ClientID, int ClaimID) {
/*var q = */ return (from d in camOnlineDb.Details
join a in camOnlineDb.Areas
on new { a = d.ClientID, b = d.AreaID ?? 0 }
equals new { a = a.ClientID, b = a.AreaID }
where d.ClientID == ClientID
join r in camOnlineDb.Reasons
on new { a = d.ClientID, b = d.ReasonID ?? 0 }
equals new { a = r.ClientID, b = r.ReasonID }
join sd in camOnlineDb.SuppDepts
on new { a = d.ClientID, b = d.CategoryID ?? 0 }
equals new { a = sd.ClientID, b = sd.CategoryID } into sdd
from sd in sdd.DefaultIfEmpty()
join h in camOnlineDb.Headers
on new { d.ClientID, d.ClaimID}
equals new { h.ClientID, h.ClaimID }
where h.ClaimID == ClaimID
join su in camOnlineDb.Suppliers
on new { h.ClientID, h.SupplierID }
equals new {su.ClientID, su.SupplierID }
join cp in camOnlineDb.ClaimPacks
on new { h.ClientID, h.ClaimID }
equals new { cp.ClientID, cp.ClaimID }
join rev in camOnlineDb.Reviews
on new { h.ClientID, h.ReviewID }
equals new { rev.ClientID, rev.ReviewID }
join revp in camOnlineDb.ReviewPeriods
on new { a = rev.ClientID, b = rev.ReviewPeriodID ?? 0 }
equals new { a = revp.ClientID, b = revp.ReviewPeriodID }
join st in camOnlineDb.Statuses
on new { a = d.ClientID, b = d.StatusID ?? 0 }
equals new { a = st.ClientID, b = st.StatusID }
join stcm in camOnlineDb.StatusCategoryMappings
on new { st.ClientID, st.StatusID }
equals new { stcm.ClientID, stcm.StatusID }
join stc in camOnlineDb.StatusCategories
on new { stcm.StatusCategoryID }
equals new { stc.StatusCategoryID }
where stc.StatusCategoryTypeID == 1
select new ClaimNumberReport {
TypeID = d.ClaimTypeID,
CPAttached = cp.FileName,
ReviewPeriodName = revp.ReviewPeriodName,
ClaimID = d.ClaimID,
Line = d.ClaimLine,
AccountNo = su.AccountNo,
SupplierName = su.SupplierName,
Amount = d.Amount,
Status = st.StatusDesc,
DateSent = d.DateSent,
DayOS = d.DaysOS,
NominalPeriod = d.NominalPeriod,
SLInvoiceNo = d.SLInvoiceNo,
Area = a.AreaDesc,
DebitRef = d.DebitFile,
DebitDate = d.JournalDate,
DeductDate = d.DeductDate,
StatusCategoryID = stc.StatusCategoryID,
StatusCategoryDesc = stc.StatusCategoryDesc,
APLReason = r.ReasonDesc,
ClientID = d.ClientID,
DeptNo = sd.DepartmentID,
DeptName = sd.DepartmentName,
Agreed = d.Agreed
});
/*return q;*/
}

This error is caused by a situation where the query result type has a column/property of non-nullable type but the generated query results in a NULL value.
This could be considered a bug or not. It is hard to see what the L2S team should have done differently here. I think they should have added a better error message. This bug is insidious because it sometimes only strikes in production under unusual data...
Your left join (sd) seem not to match and one of the sd.* properties that you select must be an int. Solve that like this:
DeptNo = (int?)sd.DepartmentID, //Cast to nullable
d.CategoryID ?? 0
What are you doing here? This seems to be a way to make the join compile. It's better to use:
join r in camOnlineDb.Reasons
on new { a = d.ClientID, b = (int?)d.ReasonID }
equals new { a = r.ClientID, b = (int?)r.ReasonID }
This cast makes the anonymous type signatures compatible. The generated SQL should now be faster. If you say x ?? 0 that converts to COALESCE(x, 0) which can prevent index use and such.

Getting a field value from a LINQ query without Iteration

I have the following query in controller and I want to store a column value in a variable but I am not being able to iterate it. Here is my code:
var srmas = (
from SRMAs in db.SRMAs
join SRMAStatus in db.SRMAStatus on SRMAs.Status equals SRMAStatus.Id
join PurchaseOrders in db.PurchaseOrders on SRMAs.PONumber equals PurchaseOrders.PONumber
join Suppliers in db.Suppliers on PurchaseOrders.SupplierID equals Suppliers.SupplierID
join SRMADetails in db.SRMADetails on SRMAs.Id equals SRMADetails.SRMAId
where(SRMAs.Id == srmaid)
group SRMADetails by new
{
SRMADetails.Id,
SRMADetails.SRMAId,
SRMADetails.SupplierPartNum,
SRMAs.PONumber,
SRMAs.ActualAmount,
SRMAs.ApprovedOn,
SRMAs.Status,
SRMAs.TrackingNumber,
SRMAs.SupplierRMANumber,
SRMAs.RequestedFromSupp,
SRMAs.CreatedOn,
Suppliers.SupplierName,
SRMAStatus.StatusName,
PurchaseOrders.PODate,
PurchaseOrders.suppliersOrderNumber
} into grp
select new
{
grp.Key.Status,
grp.Key.SRMAId,
grp.Key.Id,
grp.Key.PONumber,
grp.Key.SupplierRMANumber,
grp.Key.ActualAmount,
grp.Key.SupplierPartNum,
grp.Key.RequestedFromSupp,
grp.Key.TrackingNumber,
grp.Key.ApprovedOn,
grp.Key.SupplierName,
grp.Key.StatusName,
grp.Key.PODate,
grp.Key.suppliersOrderNumber,
grp.Key.CreatedOn,
Sum = grp.Sum(SRMADetails => SRMADetails.Cost * SRMADetails.QtyReturned)
}
).ToList();
System.Collections.IEnumerable et = (System.Collections.IEnumerable)srmas;
IEnumerator it = et.GetEnumerator();
while (it.MoveNext())
{
SRMA current = (SRMA)it.Current;
Response.Write(current.Status);
}
ViewBag.SRMAs = srmas.Select(srma => new IndexViewModel
{
Id = srma.SRMAId,
SupplierRMANum = srma.SupplierRMANumber,
SRMADetailsID = srma.Id,
PONumber = srma.PONumber,
CreatedOn = srma.CreatedOn,
SupplierName = srma.SupplierName,
SRMAStatus = srma.StatusName,
Status = srma.Status,
suppliersOrderNumber = srma.suppliersOrderNumber,
PODate = srma.PODate,
Sum = srma.Sum,
TrackingNumber = srma.TrackingNumber,
ActualAmount = srma.ActualAmount
}).ToList();
I just want to get Status value of first record. How do I do it?

Assign Distinct Object/Class in Linq to objects

I am doing following and it works:
var resultsHeader = (from r in o select new {
OrderID = r.OrderID,
subtotal = r.SubTotal,
city = r.orderAddress.BilltoCity
}).Distinct().ToList();
Look at the city = r.orderAddress.BilltoCity Line, is there any way i can populate the entire object there...like this
var resultsHeader = (from r in o select new {
OrderID = r.OrderID,
subtotal = r.SubTotal,
Address = r.orderAddress
}).Distinct().ToList();
Basicly, I want to store entire OrderAddress Object into Address property, however it does not come out as Distinct object.

You can either use DistinctBy from moreLINQ:
var resultsHeader = (from r in o select new {
OrderID = r.OrderID,
subtotal = r.SubTotal,
city = r.orderAddress.BilltoCity
}).DistinctBy(x => new { x.OrderID, x.subtotal }).ToList();
or GroupBy, which is part of LINQ already:
var resultsHeader = (from r in o
group r by new { r.OrderIs, r.SubTotal } into g
select new {
g.Key.OrderID,
g.Key.SubTotal,
Address = g.First().orderAddress
}).ToList()
UPDATE
Or, you can implement Equals and GetHashCode on your Address class and use Distinct as you do now.