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Get TOP5 records from each status using Linq C#

I have a VacancyApply table and that table consist of Status Id's,So i need Top5 data from each Status.I want to get top 5 records of each status.Status is int like 1,2,3
My Query
var result = (from ui in _context.VacancyApply
join s in _context.UserProfile on ui.UserId equals s.UserId
join x in _context.Vacancy on ui.VacancyId equals x.VacancyId
join st in _context.Status on ui.StatusId equals st.StatusId
where ui.UserId == userId && ui.IsActive == true
orderby ui.StatusId
select new VacancyApply
{
VacancyApplyId = ui.VacancyApplyId,
VacancyId = ui.VacancyId,
UserId = ui.UserId,
StatusId = ui.StatusId,
VacancyName = x.VacancyName,
VacancyStack = x.VacancyStack,
VacancyEndDate = x.VacancyEndDate,
StatusName = st.StatusName,
UserName = s.FirstName
}).ToList();

Now what I can see from the output is that it contains One VacancyId and One VendorId.
I have a feeling that you have Many to Many relationships between Vacancy and Status tables.
But nevertheless, the answer is very simple: you need to use LINQ Take extension method (maybe it will be good to make it follow after the OrderBy because just taking the last items doesn't make sense without some logic):
var output = (logic to join, filter, etc.).OrderBy(lambda).Take(N); // N is the number of
// items you want to select
Now if you want Generally to take the last items from Vacancy and only after join it with Status do this:
var output = Vacancy.OrderBy(lambda).Take(N).(now join, filter, etc. with other tables);
However, if you want to Group all similar Statuses in conjunction with Vacancies and only after taking the Top items, use GroupBy:
var output = (logic to join, filter, etc.).GroupBy(st => st.StausId).
.Select(group => group.OrderBy(lambda).Take(N));

how to get the max value of id from second table using join in entity framework in asp.net c#

I have two tables, from 1st table i want to get all records and from 2nd table i want the max id value of that record. I am using entity framework in asp.net c#.
i tried the below code but it takes only single record from first table i.e tblblogs. and leave all the records, how to get all those records by using this query? plz help me out I'll be very grateful to you. Thanks !
var query= (from c in db.tblBlogs join a in db.tblBlogMedias on c.id
equals a.BlogId where c.id==db.tblBlogMedias.Max(p=>p.id)
select new
{}

If I understood, you want to get an object with specific fields of Blogs and a list of tblBlogMedias.
You could try this code:
var query2 = (from c in db.tblBlogs
orderby c.Id descending
group c.tblBlogMedias by new { c.Id, c.Name } into gb //It will show Id and name of tblBlogs, you can use more fields if you want
select new {
Id = gb.Key.Id,
Name = gb.Key.Name, //I don't know if you have this field, but you should change it
SecondTable = gb.ToList()
})
.OrderByDescending(o => o.Id) //this orderby with FirstOrDefault() replace where c.id==db.tblBlogMedias.Max(p=>p.id)
.FirstOrDefault();

Linq InnerJoin 4 tables

My goal is to return a list of orders that only contain orderItems that are from a specific merchant. My current solution is to iterate through EVERY order, then through every order item and every listing. I imagine that is not the best practice, but I am having a hard time figuring out how to construct a single query to retrieve merchant specific orders.
I have 4 tables
Merchants(the id field being merchantID)
Orders(the id field is orderID)
orderItems(the id field is orderItemID, and FK listingID)
listings(the id field is listingID, and FK merchantID)

You can use .Any() to help you get to where you want:
var ordersFromMerchant = db.Orders
.Where(o => o.Items.Any(oi => oi.Listing.merchantID = 10);
I've made assumptions about the names of your navigation properties, but you should be able to adapt this if they don't match.
If you prefer the linq syntax, you can use:
var ordersFromMerchant = from o in db.Orders
join oi in db.orderItems on o.orderID equals oi.orderID
join l in db.listings on oi.listingID equals l.listingID
where l.merchantID = 10
select o;

I don't know your structure but something like this should work.
var query = from o in orders
join oi in orderItems on o.id equals io.orderID
join l in listings on oi.listingID equals l.id
where l.merchantID == merchantID
select o;

Linq where statement one to many

Table "aaa" have a column with foreign key to table "bbb" that in turn have it to table "ddd". Table "ddd" have a column with an ID called "costRef"
I want to select those "aaa" that have any of my "ddd" with a specific costRef that my list contains.
var query =
from tr in db.aaa
where tr.bbb.Any(x => x.ccc.ddd.Any(y => intList.Contains(y.costRef)))
select tr;
In that case above I got all of my "aaa" if any have that ref. I can understand that, but it's not what I want :) But How do I manage to do this?
Tried allot with select and where statements instead of my "any". Proberly that's the way to do it but I cant manage it.

I did SQL before Linq was around, so I still tend to follow the same structure. In this case you could just do:
var query = from a in db.aaa
join b in db.bbb on a.FK equals b.ID
join c in db.ccc on b.FK equals c.ID
where intList.Contains(c.costRef)
select a

Adding a calculated field in LINQ select results?

I have a LINQ query (using with EF)
Basically I want to add a column in Select results based on value of another column.
I have PaymentDate column in DB table but not Paid column. If there is null in PaymentDate column it also shows payment is false and if it has some date in it means paid is true.
Here is my query, please guide me how to do that.
var selectedResults=
from InvoiceSet in Invoices
join BookedAreasSet in BookedAreas
on InvoiceSet.InvoiceID equals BookedAreasSet.InvoiceID
join AreaSet in Areas on BookedAreasSet.AreaID equals AreaSet.AreaID
select new {InvoiceSet.InvoiceNumber,InvoiceSet.Amount,InvoiceSet.TotalDiscount,InvoiceSet.GST, InvoiceSet.PaymentDate,InvoiceSet.ShoppingCentreID,BookedAreasSet.BookedAreaID,
AreaSet.Name,Here I want to add calculated value column based on InvoiceSet.PaymentDate value}

I think you should be able to do something like this
var selectedResults=
from InvoiceSet in Invoices
join BookedAreasSet in BookedAreas
on InvoiceSet.InvoiceID equals BookedAreasSet.InvoiceID
join AreaSet in Areas on BookedAreasSet.AreaID equals AreaSet.AreaID
select new { InvoiceSet.InvoiceNumber,InvoiceSet.Amount,InvoiceSet.TotalDiscount,InvoiceSet.GST,
InvoiceSet.PaymentDate,InvoiceSet.ShoppingCentreID,BookedAreasSet.BookedAreaID,
AreaSet.Name,Paid = (InvoiceSet.PaymentDate == null) }