I try to make the following query using Account, Case and Activity entities :
*var findCases =
from a in context.AccountSet
join c in context.IncidentSet
on a.AccountId equals c.CustomerId.Id
join p in context.ActivityPointerSet
on c.Id equals p.RegardingObjectId.Id
select new
{
TicketNumber = c.TicketNumber,
IncidentId = c.IncidentId,
CreatedOn = c.CreatedOn,
StateCode = c.StateCode,
AccountName = a.Name
};*
The execution of this query gives the error:
AttributeFrom and AttributeTo must be either both specified or both ommited. You can not pass only one or the other. AttributeFrom: , AttributeTo: regardingobjectid
Any suggestion will be appreciated.
Regards.
Radu Antonache
Remove CasesForAccount from the query..
*var findCases =
from a in context.AccountSet
join c in context.IncidentSet
on a.AccountId equals c.CustomerId.Id
join p in context.ActivityPointerSet
on c.Id equals p.RegardingObjectId.Id
select new
{
TicketNumber = c.TicketNumber,
IncidentId = c.IncidentId,
CreatedOn = c.CreatedOn,
StateCode = c.StateCode,
AccountName = a.Name
};*
Related
I am sql query us producing correct result, but when i'm doing the same in LINQ. Output is incorrect. Please let me know where my making mistake.
Following linq query that i created.
LINQ Query:
List<UserModel> Model = (from users in db.UserM
join ct in db.CustT on users.UserId equals ct.UserID into group1
from g1 in group1.DefaultIfEmpty()
join ti in db.TestIn on g1.TestId equals ti.TestID into group2
from g2 in group2.DefaultIfEmpty()
where (users.CustomerId==CustomerId) && (users.RoleId == 4) && (users.Status == 1)
group new
{
g2.TestInvitationID,
g2.TestID,
}
by new
{
users.FirstName,
users.CreatedOn,
users.Email,
users.UserId
} into group4
select new UserModel
{
Name = group4.Key.FirstName,
CreatedOn = group4.Key.CreatedOn,
EmailId = group4.Key.Email,
UserId = group4.Key.UserId,
NoOfTestTaken = group4.Select(x=>x.TestID).Distinct().Count(),
NoOfInvitationsSent = group4.Count(x => x.TestInvitationID != 0)
}).ToList();
SQL Query:
SELECT IsNull(COUNT(distinct TS.TestId),0) AS NoOfTests,
IsNull(COUNT(TS.TestInvitationID),0) AS NoOfInvitations,
UM.Email,
UM.UserId,
UM.FirstName,
UM.CreatedOn
FROM UserM as UM
left JOIN CustT AS CT
ON UM.UserId=CT.UserId
left JOIN TestIn AS TS
ON TS.TestId = CT.TestId
WHERE UM.CustomerId=41
AND UM.RoleId=4
and UM.[Status]=1
GROUP BY UM.UserId, UM.Email, UM.FirstName, UM.CreatedOn
Tables:
"UserM" - columns: UserId, Email, FirstName, CreatedOn
"CustT" - columns: TestId, UserId,
"TestIn" - columns: TestInvitationId, TestId
The difference between SQL COUNT(expr) and LINQ Count is that the former excludes NULL values, which produces a difference when used on right side of a left outer join with no matching records (SQL will produce 0 while LINQ 1). The closest LINQ equivalent is Count(expr != null).
So the direct translation of your SQL query would be like this (note that the generated SQL query could and most likely will be different):
(A side note: When converting SQL query to LINQ, it's good to use the same aliases to make it easier to see the mappings)
var query =
from um in db.UserMasters
join ct in db.CustTests on um.UserId equals ct.UserID
into ctGroup from ct in ctGroup.DefaultIfEmpty() // left outer join
join ts in db.TestInvitaions on ct.TestId equals ts.TestID
into tsGroup from ts in tsGroup.DefaultIfEmpty() // left outer join
where um.CustomerId == UserSession.CustomerId
&& um.RoleId == 4
&& um.Status == 1
group ts by new { um.UserId, um.Email, um.FirstName, um.CreatedOn } into g
select new UserModel
{
Name = g.Key.FirstName,
CreatedOn = g.Key.CreatedOn,
EmailId = g.Key.Email,
UserId = g.Key.UserId,
NoOfTestTaken = g.Where(ts => ts != null).Select(ts => ts.TestID).Distinct().Count(),
NoOfInvitationsSent = g.Count(ts => ts != null)
};
var result = query.ToList();
I suspect that the following row is the problem because is not the same like in your sql:
Linq:
NoOfInvitationsSent = group4.Count(x => x.TestInvitationID != 0)
SQL:
IsNull(COUNT(TS.TestInvitationID),0) AS NoOfInvitations
Due to counting items from a left join Linq should be instead:
NoOfInvitationsSent = group4.Where(i => i != null).Count()
To put it all together, with a bit of better formatting:
var model = (from users in db.UserMasters
join ct in db.CustTests on users.UserId equals ct.UserID into group1
from ct in group1.DefaultIfEmpty()
join ti in db.TestInvitaions on ct.TestId equals ti.TestID into group2
from ct in group2.DefaultIfEmpty()
where users.CustomerId == UserSession.CustomerId &&
users.RoleId == 4 &&
users.Status == 1
group new { ct.TestInvitationID, ct.TestID }
by new
{
users.FirstName,
users.CreatedOn,
users.Email,
users.UserId
} into grouping
select new UserModel
{
Name = grouping.Key.FirstName,
CreatedOn = grouping.Key.CreatedOn,
EmailId = grouping.Key.Email,
UserId = grouping.Key.UserId,
NoOfTestTaken = grouping.Where(i => i != null).Select(x => x.TestID).Distinct().Count(),
NoOfInvitationsSent = grouping.Where(i => i != null).Count()
}).ToList();
I am trying to write my first query in LINQ
This is my SQL query
SELECT P.id,PS.Id,P.CPersonName
,PS.StartDate FROM Provider P
LEFT OUTER JOIN ProviderSubscription PS ON
P.id=PS.providerID
AND PS.Id=(SELECT max(id)from ProviderSubscription where
providerSubscription.ProviderId=Provider.id)
And so far i wrote this LINQ.
var query = (from p in db.Providers
join ps in db.ProviderSubscriptions on p.Id
equals ps.ProviderId
select new ViewModel
{
providerid = p.Id,
providername = p.ProviderName,
subscriptiondate = ps.ExpiryDate,
}).ToList();
I am unable to add this part in my LINQ.
AND PS.Id=(SELECT max(id)from ProviderSubscription where
providerSubscription.ProviderId=Provider.id)
I don't think you need a subquery, when you're doing a join with same tables and with same conditions then there is NO need to again write an inner query with same tables. Below query should return same result:
var query = (from p in db.Providers
join ps in db.ProviderSubscriptions on p.Id equals ps.ProviderId
where ps.Contains(ps.Max(u=>u.id))
select new ViewModel
{
providerid = p.Id,
providername = p.ProviderName,
subscriptiondate = ps.ExpiryDate,
}).ToList();
So I have few tables and i want inner join it information two create
new object. But I have a little bit trouble.
One my table have connection one to many, and when linq request , it
give me more result than i want , he just copy information. I need
request something like this:
IPagedList<HelperListings> srch = (from l in db.gp_listing
where l.DateCreated > weekago
join lp in db.gp_listing_photo on l.Id equals lp.ListingId
join loc in db.gp_location on l.LocationId equals loc.Id
orderby l.DateCreated ascending
select new HelperListings { id = l.Id, HouseNumber = l.HouseNumber,ListingPrice = l.ListingPrice, PhotoUrl = lp.PhotoUrl.First(), AreaStateCode = loc.AreaStateCode }).ToList().ToPagedList(page ?? 1, 15);
PhotoUrl = lp.PhotoUrl.First() i need something like this but i don`t have any ideas how to do it. Need ur help guys.
UPDATE :
Responding to your comment, you have at least 2 options : 1. use group by and select only the first PhotoUrl from each group, or 2. don't join to gp_listing_photo table to avoid duplicated rows, and use subquery to get only the first PhotoUrl. Example for the latter :
IPagedList<HelperListings> srch =
(from l in db.gp_listing
where l.DateCreated > weekago
join loc in db.gp_location on l.LocationId equals loc.Id
orderby l.DateCreated ascending
select new HelperListings
{
id = l.Id,
HouseNumber = l.HouseNumber,
ListingPrice = l.ListingPrice,
PhotoUrl = (from lp in db.gp_listing_photo where l.Id = lp.ListingId select lp.PhotoUrl).FirstOrDefault(),
AreaStateCode = loc.AreaStateCode
}
).ToList().ToPagedList(page ?? 1, 15);
How about simply appending .Distinct() after your LINQ query to avoid duplicated data :
IPagedList<HelperListings> srch =
(from l in db.gp_listing
where l.DateCreated > weekago
join lp in db.gp_listing_photo on l.Id equals lp.ListingId
join loc in db.gp_location on l.LocationId equals loc.Id
orderby l.DateCreated ascending
select new HelperListings
{
id = l.Id,
HouseNumber = l.HouseNumber,
ListingPrice = l.ListingPrice,
PhotoUrl = lp.PhotoUrl,
AreaStateCode = loc.AreaStateCode
}
).Distinct().ToList().ToPagedList(page ?? 1, 15);
For Reference : LINQ Select Distinct with Anonymous Types
i am trying to join my linq query with another table. How can I display the name in the Customer table? I am getting an error: does not contain a definition for 'Name'?
from p in Purchases
join c in Customers on p.CustomerID equals c.ID
group p by p.Date.Year into SalesPerYear
select new {
customername= SalesPerYear.First().Name,
customerid= SalesPerYear.First().CustomerID,
totalsales= SalesPerYear.Sum(x=>x.Price)
}
You're grouping p (i.e. purchases) by date - so the customer details are no longer present.
Try this instead:
from p in Purchases
join c in Customers on p.CustomerID equals c.ID
group new { p, c } by p.Date.Year into SalesPerYear
select new {
CustomerName = SalesPerYear.First().c.Name,
CustomerId = SalesPerYear.First().p.CustomerID,
TotalSales = SalesPerYear.Sum(x => x.p.Price)
}
Or alternatively:
from p in Purchases
join c in Customers on p.CustomerID equals c.ID
group new { p.CustomerId, p.Price, c.CustomerName }
by p.Date.Year into SalesPerYear
select new {
SalesPerYear.First().CustomerName,
SalesPerYear.First().CustomerId
TotalSales = SalesPerYear.Sum(x => x.Price)
}
SalesPerYear is an IGrouping. You need to access Name, CustomerID etc off the Value property of the IGrouping.
I have a query that has the following
var myvar = from table in MyDataModel
where.....
select new MyModel
{
modelvar1 = ...,
modelvar2 = (from..... into anothervar)
}
What I want to do is have modelvar2 be a join between the result I currently get from anothervar with another table in MyDataModel.
Thanks
The parenthesis looks more like a subquery than a join. This is how you do a join.
Example tables from the AdventureWorks database.
using (DataClasses1DataContext context = new DataClasses1DataContext())
{
// If you have foreign keys correctly in your database you can
// join implicitly with the "dot" notation.
var myvar = from prod in context.Products
where prod.ListPrice < 10
select new
{
Name = prod.Name,
Category = prod.ProductSubcategory.ProductCategory.Name,
};
// If you don't have foreign keys you need to express the join
// explicitly like this
var myvar2 = from prod in context.Products
join prodSubCategory in context.ProductSubcategories
on prod.ProductSubcategoryID equals prodSubCategory.ProductSubcategoryID
join prodCategory in context.ProductCategories
on prodSubCategory.ProductCategoryID equals prodCategory.ProductCategoryID
where prod.ListPrice < 10
select new
{
Name = prod.Name,
Category = prodCategory.Name,
};
// If you REALLY want to do a subquery, this is how to do that
var myvar3 = from prod in context.Products
where prod.ListPrice < 10
select new
{
Name = prod.Name,
Category = (from prodSubCategory in context.ProductSubcategories
join prodCategory in context.ProductCategories
on prodSubCategory.ProductCategoryID equals prodCategory.ProductCategoryID
select prodCategory.Name).First(),
};
// If you want to get a list from the subquery you can do like this
var myvar4 = from prodCategory in context.ProductCategories
select new
{
Name = prodCategory.Name,
Subcategoreis = (from prodSubCategory in context.ProductSubcategories
where prodSubCategory.ProductCategoryID == prodCategory.ProductCategoryID
select new { prodSubCategory.ProductSubcategoryID, prodSubCategory.Name }).ToList(),
};
}
SELECT [t0].[OrderID], [t0].[CustomerID], [t0].[EmployeeID], [t0].[OrderDate], [t0].[RequiredDate], [t0].[ShippedDate], [t0].[ShipVia], [t0].[Freight], [t0].[ShipName], [t0].[ShipAddress], [t0].[ShipCity], [t0].[ShipRegion], [t0].[ShipPostalCode], [t0].[ShipCountry]
FROM [Orders] AS [t0]
INNER JOIN ([Order Details] AS [t1]
INNER JOIN [Products] AS [t2] ON [t1].[ProductID] = [t2].[ProductID]) ON [t0].[OrderID] = [t1].[OrderID]
can be write as
from o in Orders
join od in (
from od in OrderDetails join p in Products on od.ProductID equals p.ProductID select od)
on o.OrderID equals od.OrderID
select o