LINQ join issue, returns all null value - linq

Question

I am new in EF and LINQ and I am facing a strange issue. When I check null value in my select new block, all values from child table is coming null. Below is the LINQ query.
My Linq Code
var linqResult = from pd in entities.tblpackagedetails
join ps in entities.tblpackageselecteds
on pd.PackageDetailsID equals ps.PackageDetailsID
into tabJoin
from tj in tabJoin.Where(ps => ps.UserID == userID
&& ps.IsActive == true).DefaultIfEmpty()
select new
{
IsComplete = (tj == null) ? false : tj.IsComplete,
IsActive = (tj == null) ? false : tj.IsActive,
UserID = (tj == null) ? 0 : tj.UserID,
IsMandatory = pd.IsMandatory,
PackageSelectedID = (tj == null) ? 0 : tj.PackageSelectedID,
IsSelected = (tj == null ? false : tj.IsSelected),
pd.Amount,
pd.Code,
pd.Description,
pd.Points,
pd.PackageDetailsID
};
foreach (var result in linqResult)
{
packagesSelected.Add(new PackageDetailDataModel()
{
Amount = result.Amount,
Code = result.Code,
Description = result.Description,
IsComplete = result.IsComplete,
IsMandatory = result.IsMandatory,
PackageDetailsID = result.PackageDetailsID,
PackageSelectedID = result.PackageSelectedID,
Points = result.Points,
IsActive = result.IsActive,
UserID = result.UserID,
IsSelected = result.IsSelected
});
}
SQL generated by Visualizer
SELECT
`Extent1`.`PackageDetailsID`,
`Extent2`.`IsComplete`,
`Extent2`.`IsActive`,
`Extent2`.`UserID`,
`Extent1`.`IsMandatory`,
`Extent2`.`PackageSelectedID`,
`Extent2`.`IsSelected`,
`Extent1`.`Amount`,
`Extent1`.`Code`,
`Extent1`.`Description`,
`Extent1`.`Points`
FROM `tblpackagedetails` AS `Extent1`
LEFT OUTER JOIN `tblpackageselected` AS `Extent2`
ON (`Extent1`.`PackageDetailsID` = `Extent2`.`PackageDetailsID`)
AND ((`Extent2`.`UserID` = #linq_0) AND (1 = `Extent2`.`IsActive`))
When I ran above sql in MySQL workbench I got below output (repalcing #linq_0 with userID).
My Parent Table Structure
Child Table Structure
Output I want
But the values for IsComplete, IsActive, UserID, PackageSelectedID and IsSelected null as a result condition checking in select new block assign false or 0.
If I remove null checking, I get value for first 3 rows and in fourth iteration I get below exception.
The cast to value type 'Boolean' failed because the materialized value is null. Either the result type's generic parameter or the query must use a nullable type
Please help... :(
Working code block
packagesSelected = new List<PackageDetailDataModel>();
var linqResult = from pd in entities.tblpackagedetails
join ps in entities.tblpackageselecteds
on pd.PackageDetailsID equals ps.PackageDetailsID
into tabJoin
from tj in tabJoin.Where(ps => ps.UserID == userID
&& ps.IsActive == true).DefaultIfEmpty()
select new
{
IsComplete = (bool?)tj.IsComplete,
IsActive = (bool?)tj.IsActive,
UserID = (int?)tj.UserID,
IsMandatory = pd.IsMandatory,
PackageSelectedID = (int?)tj.PackageSelectedID,
IsSelected = (bool?)tj.IsSelected,
pd.Amount,
pd.Code,
pd.Description,
pd.Points,
pd.PackageDetailsID
};
foreach (var result in linqResult)
{
packagesSelected.Add(new PackageDetailDataModel()
{
Amount = result.Amount,
Code = result.Code,
Description = result.Description,
IsComplete = (result.IsComplete ?? false),
IsMandatory = result.IsMandatory,
PackageDetailsID = result.PackageDetailsID,
PackageSelectedID = (result.PackageSelectedID ?? 0),
Points = result.Points,
IsActive = (result.IsActive ?? false),
UserID = (result.UserID ?? 0),
IsSelected = (result.IsSelected ?? false)
});
}
Thanks to 2Kay :)

Answer 1

When tj is null, EF consieders all properties of tj as null. It's ok, but when EF trying to materialize them into value-types it fails. So the solution is to use nullable types..
Try this query:
var linqResult = from pd in entities.tblpackagedetails
join ps in entities.tblpackageselecteds
on pd.PackageDetailsID equals ps.PackageDetailsID
into tabJoin
from tj in tabJoin.Where(ps => ps.UserID == userID
&& ps.IsActive == true).DefaultIfEmpty()
select new
{
IsComplete = (bool?) tj.IsComplete,
IsActive = (bool?) tj.IsActive,
UserID = (int?) tj.UserID,
IsMandatory = pd.IsMandatory,
PackageSelectedID = (int?) tj.PackageSelectedID,
IsSelected = (bool?) tj.IsSelected,
pd.Amount,
pd.Code,
pd.Description,
pd.Points,
pd.PackageDetailsID
};