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convert rows to column in entity framwork

how can i convert rows to column in entity framework!?
i have a result like this:
and i want this result:
my entity code i this :
(from loanPerson in context.LoanPersons.AsParallel()
join warranter in context.Warranters.AsParallel() on loanPerson.Id equals warranter.LoanPersonId
where loanPerson.Id == 84829
select new
{
loanPersonId = loanPerson.Id,
waranterId = warranter.WarranterPersonID,
}).ToList();
and number of the row always less than 3 and i want to have 3 column.
please let me know your answer.
tanks.

This query will return the only one row, where waranterIds will contain, at this particular case, three WarranterPersonID values, also this field is of List<int> type, because it's quantity not known at compile time:
var answer = (from loanPerson in context.LoanPersons.Where(x => x.Id == 84829)
join warranter in context.Warranters
on loanPerson.Id equals warranter.LoanPersonId
group warranter by loanPerson.Id into sub
select new
{
loanPersonId = sub.Key,
waranterIds = sub.Select(x => x.LoanPersonId).ToList()
//if you sure, that quantity equals 3,
//you can write this code instead of waranterIds:
//zamen1 = sub.Select(x => x.LoanPersonId).First(),
//zamen2 = sub.Select(x => x.LoanPersonId).Skip(1).First(),
//zamen3 = sub.Select(x => x.LoanPersonId).Skip(2).First()
}).ToList();

How do I drill down to specific data in my LINQ query result?

I want to drill down into a particular item in my data and output the list of results to the output window. My query result looks like this
private IEnumerable<DataRow> _data;
var query = from data in this._data
group data by data.Field<string>("Form Name") into groups //same as Form ID
select new
{
formName = groups.Key,
items = from d in groups
group d by d.Field<string>("Item Name") into grps
let name = grps.Key
let documentIDGroups = grps.GroupBy(t => t.Field<string>("Document ID"))
let documentIDGroupsCount = documentIDGroups.Count()
let distinctDocumentValueCount = from data in documentIDGroups
select new
{
docID = data.Key,
distinctDocValueCount = data.Where(t => string.IsNullOrEmpty(t.Field<string>("Document Value").Trim()) == false).Select(t => t.Field<string>("Document Value")).Distinct().Count()
}
let sum = distinctDocumentValueCount.Sum(t => t.distinctDocValueCount)
let distinctItemsNames = from data in grps
select data.Field<string>("Item Name").Distinct().Count()
let count = distinctItemsNames.Count()
select new
{
itemName = name,
documentIDGroups,
documentIDGroupsCount,
averageChoices = Math.Round(((decimal)sum / documentIDGroupsCount), 2),
distinctDocumentValueCount,
sum
}
};
So on that query result I want to drill down into a particular form name, and from there get a particular Item Name and so on
so the first step is to get the grouping of items and I have
var items = from d in query where d.formName == "someName" select d.items;
but I don't know how to isolate the items by a particular string.
I want to do the following
var item = from d in items where d.itemName == "anItemName" select d;
But I don't know the syntax.

Use the .FirstOrDefault extension if you expect a single item to be returned from your query. SO:
var item = (from d in items where d.itemName == "anItemName" select d).FirstOrDefault();

The LINQ expression contains references to queries that are associated with different contexts

Here's my code:
var myStrings = (from x in db1.MyStrings.Where(x => homeStrings.Contains(x.Content))
join y in db2.MyStaticStringTranslations on x.Id equals y.id
select new MyStringModel()
{
Id = x.Id,
Original = x.Content,
Translation = y.translation
}).ToList();
And I get the error that the specified LINQ expression contains references to queries that are associated with different contexts. I know that the problem is that I try to access tables from both db1 and db2, but how do I fix this?

MyStrings is a small table
Load filtered MyStrings in memory, then join with MyStaticStringTranslations using LINQ:
// Read the small table into memory, and make a dictionary from it.
// The last step will use this dictionary for joining.
var byId = db1.MyStrings
.Where(x => homeStrings.Contains(x.Content))
.ToDictionary(s => s.Id);
// Extract the keys. We will need them to filter the big table
var ids = byId.Keys.ToList();
// Bring in only the relevant records
var myStrings = db2.MyStaticStringTranslations
.Where(y => ids.Contains(y.id))
.AsEnumerable() // Make sure the joining is done in memory
.Select(y => new {
Id = y.id
// Use y.id to look up the content from the dictionary
, Original = byId[y.id].Content
, Translation = y.translation
});

You are right that db1 and db2 can't be used in the same Linq expression. x and y have to be joined in this process and not by a Linq provider. Try this:
var x = db1.MyStrings.Where(xx => homeStrings.Contains(xx.Content)).ToEnumerable();
var y = db2.MyStaticStringTranslations.ToEnumerable();
var myStrings = (from a in x
join b in y on x.Id equals y.id
select new MyStringModel()
{
Id = x.Id,
Original = x.Content,
Translation = y.translation
}).ToList();
Refer to this answer for more details: The specified LINQ expression contains references to queries that are associated with different contexts
dasblinkenlight's answer has a better overall approach than this. In this answer I'm trying to minimize the diff against your original code.

I also faced the same problem:
"The specified LINQ expression contains references to queries that are associated with different contexts."
This is because it's not able to connect to two context at a time so i find the solution as below.
Here in this example I want to list the lottery cards with the owner name but the Table having the owner name is in another Database.So I made two context DB1Context and DB2Context.and write the code as follows:
var query = from lc in db1.LotteryCardMaster
from om in db2.OwnerMaster
where lc.IsActive == 1
select new
{
lc.CashCardID,
lc.CashCardNO,
om.PersonnelName,
lc.Status
};
AB.LottryList = new List<LotteryCardMaster>();
foreach (var result in query)
{
AB.LottryList.Add(new LotteryCardMaster()
{
CashCardID = result.CashCardID,
CashCardNO = result.CashCardNO,
PersonnelName =result.PersonnelName,
Status = result.Status
});
}
but this gives me the above error so i found the other way to perform joining on two tables from diffrent database.and that way is as below.
var query = from lc in db1.LotteryCardMaster
where lc.IsActive == 1
select new
{
lc.CashCardID,
lc.CashCardNO,
om.PersonnelName,
lc.Status
};
AB.LottryList = new List<LotteryCardMaster>();
foreach (var result in query)
{
AB.LottryList.Add(new LotteryCardMaster()
{
CashCardID = result.CashCardID,
CashCardNO = result.CashCardNO,
PersonnelName =db2.OwnerMaster.FirstOrDefault(x=>x.OwnerID== result.OwnerID).OwnerName,
Status = result.Status
});
}

Linq to SQL joining two tables and populate GridView

I have two tables in my database, Building and Town. They look like this:
Building:
buildingid
buildingname
Town:
id
userid
buildingid
In Town there is one entry for each building a user has.
What i want is to populate a GridView for a user with a given userid. This GridView should include the buildingname and the number of buildings.
Building. I have tried this:
var buildings = (from Town in dc.Towns
join Building in dc.Buildings
on Town.buildingid equals Building.buildingid
select Building.buildingname);
gvBuildings.DataSource = buildings;
gvBuildings.DataBind();
But I don't know how to get the numbers for each building.
I have now been working on this for a while and a couple of your answers work. I have used this code:
var buildings = dc.Towns
.Where(t => t.userid == userid)
.GroupJoin(dc.Buildings,
t => t.buildingid,
b => b.buildingid,
(Town, Buildings) => new
{
BuildningName = Buildings.First().buildingname,
Count = Buildings.Count()
});
gvBuildings.DataSource = buildings.ToList();
gvBuildings.DataBind();
When i run this code my GridView ends up looking like this:
I need the buildings to be shown in groups, grouped by the buildingname. I have tried all of the suggestions but i cant get it to work.

Try grouping:
var buildings = dc.Towns
.Where(t => t.UserId == userId)
.GroupJoin(dc.Buildings,
t => t.BuildingId,
b => b.BuildingId,
(town, buildings) => new
{
BuildingName = buildings.First().BuildingName,
Count = buildings.Count
});
Keep in mind that when binding to a control you must supply a collection of type (or implementing) IList. This can be accomplished by calling ToList() on the buildings collection:
gvBuildings.DataSource = buildings.ToList();
gvBuildings.DataBind();

check linq differed execution
and than try the blow code might work for you
var buildings =
(from j in dc.Town
join i in dc.Buildings
on j.buildingId equals i.buildingId
where j.Userid = varUSerid
group new {i, j}
by new
{ i.BuildingID }
into
g
select new {
BuildingName = g.First<k=>k.BuildingName)
, count = g.Count() } ).ToList();
gvBuildings.DataSource = buildings;
gvBuildings.DataBind();

var buildings = (from Town in dc.Towns
join Building in dc.Buildings
on Town.buildingid equals Building.buildingid
into results
from r in results.DefaultIfEmpty()
group Town by new
{
r.BuildingId
} into groupedResults
where Town.UserID == parameteruserId
select new
{
BuildingName = Building.buildingname,
BuildingCount = groupedResults.Count()
});
Try this.. it should work.. i have a similar requirement..

manDbDataContext db = new DbDataContext();
var estimatedTotal = ( from est in db.AssignmentEstimatedMaterials
where est.assignment_id == Convert.ToInt32(Label_assignmentId.Text)
join materialdetail in db.Materials on est.material_id equals materialdetail.material_id
select new { est.qty,est.total_amount, materialdetail.material_name}).ToList();
GridView_estiamte_material.DataSource = estimatedTotal;
GridView_estiamte_material.DataBind();
Note, you should select individual data and it works.

linq-to-sql getting sequence contains more than one element

I have a query that looks like this: it takes a list of IDs (ThelistOfIDs) as parameter and I'm grouping for a count.
var TheCounter = (from l in MyDC.SomeTable
where ThelistOfIDs.Contains(l.ID)
group l by l.Status into groups
select new Counter()
{
CountOnes = (from g in groups
where g.Status == 1
select g).Count(),
CountTwos = (from g in groups
where g.Status == 2
select g).Count(),
}).Single();
And basically, I don't understand why I'm getting the error. I don't want to brring back the entore collection from the DB and do the count in linq-to-object; I want to do the count in the DB and bring back the result.

I have not put your query into my IDE or compiled with C#, but I guess the problem is that
groups in your query is IGrouping<Tkey, Telm> and not IQueryable<Tkey>
(where Tkey is type of l.Status and Telm is type of l).
I think you got confused with the use of grouping operator.
What you want to get is I guess:
var queryByStatus = from l in MyDC.SomeTable
where ThelistOfIDs.Contains(l.ID)
group l by l.Status;
var counter = new Counter()
{
CountOnes = queryByStatus.Where(l => l.Key == 1).Count(),
CountTwos = queryByStatus.Where(l => l.Key == 2).Count(),
};
EDIT:
Alternative query, to obtain the same, moving all operation on DB into the original query so that DB is queried only once.
var queryCountByStatus = from l in MyDC.SomeTable
where ThelistOfIDs.Contains(l.ID)
group l by l.Status into r
select new { status = r.Key, count = r.Count() };
var countByStatus = queryCountByStatus.ToList();
var counter = new Counter()
{
CountOnes = countByStatus.FirstOrDefault(l => l.status == 1).count,
CountTwos = countByStatus.FirstOrDefault(l => l.status == 2).count,
};
Note:
The query in my edit section queries the DB once only and mapping Status -> Count is returned.
Note that in my original query there were two calls to DB needed only - both of which returned single number - one for CountOnes, one for CountTwos.
In the edit query, one query is done which return table { { 1, CountOnes}, {2, CountTwos } }. The other lines are just to convert the result - which is set of items - into single object having certain objects as properties and is done physically on these two values.

You are grouping by Status, and then projecting from that group - but you will still have one row per unique Status (===group).
So: I propose that you don't have exactly one unique Status.

This might be what you're looking for to get...
(it's for users table I had but should be the same)
var statuscounts = (from u in db.Users
where u.UserStatus > 0
group u by u.UserStatus into groups
select new { Status = groups.Key, Count = groups.Count() });
// do this to iterate and pump into a Counter at will
foreach (var g in statuscounts)
Console.WriteLine("{0}, {1}", g.Status, g.Count);
...or even something like this...
var counter = statuscounts.AsEnumerable()
.Aggregate(new Counter(), (c, a) => {
switch (a.Status)
{
case 1: c.CountOfOnes = a.Count; return c;
case 2: c.CountOfTwos = a.Count; return c;
case 3: c.CountOfThrees = a.Count; return c;
default: c.CountOfOthers = a.Count; return c;
}});
...point is that if you're grouping already you should use the grouping result, it's of type IGrouping<out TKey, out TElement> where the key is your status and it's IEnumerable<> or your records.
hope this helps