I have multiple linq queries that retrieve the same data just at different grouping levels. (potentially 3 different levels). The linq query currently results in an enumerable list of a custom object. The items I don't understand or wonder if possible (to reduce redundant code):
can I make the following group by clause to be dynamic?
if so, can it dynamically populate my custom object group data when it is grouped at that level.
For instance:
var myReport_GroupProductLevel =
from r in mySum_GroupProductLevel
join pc in _myPlotCount on r.Strata equals pc.Strata
join acr in _myStrataAcres on pc.Strata equals acr.Strata
group new { r, pc, acr } by new { r.Strata, pc.Count, acr.Acres, r.GroupName, r.ProductName } into g
select new DataSummary
{
Strata = g.Key.Strata,
PlotCount = g.Key.Count,
Acres = g.Key.Acres,
ClassName = string.Empty,
GroupName = g.Key.GroupName,
ProductName = g.Key.ProductName,
TPAMEAN = g.Sum(x => x.r.TPA / x.pc.Count),
TPADEV = g.Select(x => x.r.TPA).StdDev(g.Key.Count)
};
If I wanted to group only by "GroupName" instead... I would rewrite the query. Issues I see are, if I'm grouping by a value then I need that value in the query (g.Key.GroupName); but since I'm creating a new custom object the other non-grouped values such as "ClassName" require a value (I used string.Empty above, but that is static).
Thanks for any insight...
if anyone was curious, I got it to work by using a conditional statement... since grouping by empty will make it collapse.
var mySum_ClassGroupProductLevel =
from s in ReportData.myStands
join p in ReportData.myPlots on s.ID equals p.StandID
join t in ReportData.myTrees on p.ID equals t.PlotID
group t by new { s.Strata, p.ID,
ClassName = useClassName ? t.ClassName : string.Empty,
GroupName = useGroupName ? t.GroupName : string.Empty,
ProductName = useProductName ? t.ProductName : string.Empty }
into g
select new
{}
Related
Context
I am trying to get a list from select new:
var portfolioresult =
(from port in _context.Portfolio
join u in _context.Universe on port.CUSIP equals u.ID_CUSIP
join m in _context.MarketDataEvent on u.ID_CUSIP equals m.CUSIP_NUMBER_REALTIME
//select new { m, port.Name }).ToList();
select new ViewResult() { MarketDataEvents = m, PortfolioName = port.Name })
.ToList();
I want to get MarketDataEvents as List<MarketDataEvent>
Corresponding SQL query
SELECT me.*, p.Name FROM MarketDataEvent me
INNER JOIN universe u ON u.ID_CUSIP=me.CUSIP_NUMBER_REALTIME
INNER JOIN portfolio p ON p.CUSIp=me.CUSIP_NUMBER_REALTIME
Problem
I am not able to get a List inside select new. Is it possible to get something like this?
select new ViewResult() { MarketDataEvents = List<MarketDataEvents>, PortfolioName = port.Name })
Expected result
List<MarketDataEvents> "XYZ"
List<MarketDataEvents> "ABC"
Actual result
MarketDataEvent "XYZ
MarketDataEvent "XYZ"
MarketDataEvent "ABC"
Yes, it is possible:
var query =
from port in _context.Portfolio
select new ViewResult
{
MarketDataEvents =
(from u in _context.Universe.Where(u => port.CUSIP == u.ID_CUSIP)
join m in _context.MarketDataEvent on u.ID_CUSIP equals m.CUSIP_NUMBER_REALTIME
select m).ToList(),
PortfolioName = port.Name
};
var portfolioresult = query.ToList();
Essentially your m reference is out of scope. The input available to a select statement is only a single value out of the set available as a result of the select/joins you're looking at, which is why you don't see a list of all available from m, only a single value in each record.
Rather, you need to use a SelectMany since it'll expose an IEnumerable as the input to the function and you can split out the individual XYZ values out of that.
I have a very simple SQL
SELECT s.shop_code
,SUM(im.amt) sum_amt
,s.cell_no#1 shop_cell
FROM tb_sn_so_wt_mst im
,tb_cm_shop_inf s
WHERE im.shop_code = s.shop_code
GROUP BY s.shop_code, s.cell_no#1)
then i try to code linq
var listResult = from warrantyMaster in listWarrantyMasters2.Records
join shopInfo in listShopInfos
on warrantyMaster.ShopCode equals shopInfo.ShopCode
i don't know group by shop code and cell no and sum atm, any one help me out of this problem
The group by syntax with some examples is explained here group clause (C# Reference) and related links.
Here is the direct translation of your SQL query (of course the field names are just my guess since you didn't provide your classes):
var query = from im in listWarrantyMasters2.Records
join s in listShopInfos
on im.ShopCode equals s.ShopCode
group im by new { s.ShopCode, s.CellNo } into g
select new
{
g.Key.ShopCode,
g.Key.CellNo,
SumAmt = g.Sum(e => e.Amt)
};
You can try this code:
var results = from warrantyMaster in listWarrantyMasters2.Records
from shopInfo in listShopInfos
.Where(mapping => mapping.ShopCode == warrantyMaster.ShopCode )
.select new
{
ShopCode = warrantyMaster.ShopCode,
ATM = listWarrantyMasters2.ATM,
ShellNo = shopInfo.ShellNo
}
.GroupBy(x=> new { x.ShopCode, x.ShellNo })
.Select(x=>
new{
ShopCode = x.Key.ShopCode,
ShellNo = x.Key.ShellNo,
SumATM = x.Sum(item=>item.ATM)
});
I 'm trying to do a search for a contact. For example value "Café " which is stored in the name field , but when I search like "cafe" does not return any record .
I tried to do the following
using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
var query_where3 = from c in svcContext.ContactSet
join a in svcContext.AccountSet
on c.ContactId equals a.PrimaryContactId.Id
where c.FullName.Normalize(NormalizationForm.FormD).Contains("Café")
select new
{
account_name = a.Name,
contact_name = c.LastName
};
}
and appear the Exception with message saying "Invalid 'where' condition. An entity member is invoking an invalid property or method"
You can't use that functions on LinQ-CRM, the correct way to do the query is:
c.FullName == "someString" or c.FullName.equals("someString").
This is because you can't use functions or transformations on the left condition. You must use the attribute itself.
Your query will look like:
using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
var query_where3 = from c in svcContext.ContactSet
join a in svcContext.AccountSet
on c.ContactId equals a.PrimaryContactId.Id
where c.FullName == "Café" || c.FullName == "Cafe"
select new
{
account_name = a.Name,
contact_name = c.LastName
};
}
You can't really deal with the accents with Linq to SQL in general ... and you are even more limited with what you can do with Linq to CRM. You cant modify the DB; unless you don't care about being supported. Then you could do something like : MAD suggested and to a db alter.
ALTER TABLE Name ALTER COLUMN Name [varchar](100) COLLATE SQL_Latin1_General_CP1_CI_AI
I personally would not recommend that.
The best that I can come up with is getting the data as close as you can and filtering it from there inside a list or something similar.
I have to do it all the time and it is a pain (and adds more overhead) but there is not really another workaround that I have found.
//declare a dictionary
Dictionary<string, string> someDictionary = new Dictionary<string, string> ();
using (ServiceContext svcContext = new ServiceContext(_serviceProxy))
{
var query_where3 = from c in svcContext.ContactSet
join a in svcContext.AccountSet
on c.ContactId equals a.PrimaryContactId.Id
where c.FullName.Contains("Caf")
select new
{
account_name = a.Name,
contact_name = c.LastName
};
}
//then
foreach(var q in query_where3)
{
if(string.IsNullOrEmpty(account_name)==false && string.IsNullOrEmpty(contact_name)==false)
{
someDictionary.Add(account_name, contact_name);
}
}
//then you can add the .Normalize(NormalizationForm.FormD) to your dictionary
Hope that helped.
Its all about
.Normalize(NormalizationForm.FormD)
, probably EF does not knows how to handle this method. Remove it and test just with
c.FullName.Contains("Café")
------------------------------------------------- Added in 2015-01-30 --------------------------------------------------
So man, the unique solution i can think about is list before you do the where condition. This way the you can use the normalize once this will be handled by linq 2 objects. try:
(from c in svcContext.ContactSet join a in svcContext.AccountSet
on c.ContactId equals a.PrimaryContactId.Id
select new {a=a,c=c} ).ToList()
.Where(c=>c.FullName.Normalize(NormalizationForm.FormD).Contains("Café"))
.Select( x=> select new {
account_name = x.a.Name,
contact_name = x.c.LastName
};)
But that way can cause some overhead given that linq 2 obejects runs in application server memory, not in database server.
CRM's LINQ translator cannot handle the .Equals() method.
on c.ContactId equals a.PrimaryContactId.Id
Change the above line to below line.
on c.ContactId == a.PrimaryContactId.Id
from component in Materials.OfType<Container>().Where(m => m.Active)
join segmentFinanceRating in segmentFinanceRatingView on component.Id equals segmentFinanceRating.MaterialId into segmentFinanceRatingGroup
from segmentFinanceRatingWithDefault in segmentFinanceRatingGroup.DefaultIfEmpty()
select new
{
id = component.Id,
name = component.Name,
subType = component.SubType,
size = component.Size,
MaterialIds = component.Materials.Select(x => x.Id),
BrandNames = component.Brands.Select(x => x.Name),
SegmentRatings = segmentFinanceRatingWithDefault
}
I have the above LINQ to Entities query that has a LEFT JOIN to get rating values for 1 or more segments for a given component.
The segmentFinanceRating entity has the properties, { MaterialId, SegmentId, Rating, LowRated }
At the moment the results are not grouped to the relevant component, i.e. the SegmentRatings property is not a single collection of segmentFinanceRating objects, instead I have multiple data rows with 1 segmentFinanceRating object in each.
I have seen some examples of using group x by y into z but I couldn't get it working, possibly due to some of the collections on the component that I need too, I'm not sure.
Any help would be appreciated on how to do this, thanks.
GroupBy in List doesn't work for you?
var list = (from component in Materials.OfType<Container>().Where(m => m.Active)
join segmentFinanceRating in segmentFinanceRatingView on component.Id equals segmentFinanceRating.MaterialId into segmentFinanceRatingGroup
from segmentFinanceRatingWithDefault in segmentFinanceRatingGroup.DefaultIfEmpty()
select new
{
id = component.Id,
name = component.Name,
subType = component.SubType,
size = component.Size,
MaterialIds = component.Materials.Select(x => x.Id),
BrandNames = component.Brands.Select(x => x.Name),
SegmentRatings = segmentFinanceRatingWithDefault
}).ToList().GroupBy(s=> s.SegmentRatings);
In this case it's much easier to do the join in the anonymous type:
from component in Materials.OfType<Container>().Where(m => m.Active)
select new
{
id = component.Id,
name = component.Name,
subType = component.SubType,
size = component.Size,
MaterialIds = component.Materials.Select(x => x.Id),
BrandNames = component.Brands.Select(x => x.Name),
SegmentRatings = (from segmentFinanceRating in segmentFinanceRatingView
where segmentFinanceRating.MaterialId == component.Id
select segmentFinanceRating)
}
You will have an empty collection of SegmentRatings when there are none for a specific component, giving the same effect as outer join.
I am trying to pull the results from the database and set the child property while selecting using the Linq (EF V5.0). The reason I am doing this is because there is no relation in the database to use include..
var lamdaResult = from u in model.Entity_Users
join s in model.Entity_Staff on u.UserID equals s.ST_UserID
select new { u, s };
return lamdaResult.Select(x => x.u.Staff = x.s; return x.u;).FirstOrDefault();
I am learning Linq.. the above expression is giving me error.. can someone help me the best way to set the child property...
I could also do this.. but I am wondering is there any better way to fulfill the same result instead of following 2 expressions
var user=null;
var lamdaResult = from u in model.Entity_Users
join s in model.Entity_Staff on u.UserID equals s.ST_UserID
select new { u, s };
user = lamdaResult.Select(x => x.u).FirstOrDefault();
user.Staff = lamdaResult.Select(x => x.s).FirstOrDefault();
Linq is for querying, not for mutating objects. You'll need to use something other than LINQ to do the mutation, generally a foreach is appropriate, although given that you only have a single item, there's no need for even that:
var item = (from u in model.Entity_Users
join s in model.Entity_Staff on u.UserID equals s.ST_UserID
select new { User = u, Staff = s })
.FirstOrDefault();
item.User.Staff = item.Staff;
return item.User;