Return type Anonymous and searching

Question

I have a DispositionHold class created by the designer when using Linq to SQL. I want to return some fields from this class and also return a count.

 

 var query = (from disposition in db.DispositionHolds
               group disposition by new

               {
                 disposition.ReportDate,
                 disposition.FileName
               } into d
               select new
               {
                 count = d.Key.FileName.Count(),
                 d.Key.ReportDate,
                 d.Key.FileName
               });
        return query;

 I want to return a type that I can search in later. If I use IEnumerable I can return the anonymous type but I am having problems searching in the FileName field.

I tried to return a List<DispositionHold> but there is no count field of course.

I tried to return an Array type but I can't seem to search in the FileName field either.

I know I can create a class with the count field but that seems overkill since I may need to return counts for other classes.

Answer 1

You can't return anonymous types so your options are to use the actual type or to project into another existing type.

You say you don't want to return the actual type because it doesn't have a count so you could use the Tuple type in .NET 4.0 or roll your own similar generic type that could be re-used a lot.

[)amien

Answer 2

Could you please elaborate, what type is FileName?

Regards

Answer 3

Sorry. FileName is a varchar

Answer 4

If it is a varchar it is mapped as a string?  Then Count for a string doesn't exist, use Length instead assuming that what you want is to store the lenght of the FileName, if what you want is the ammount of records selected by your query then you use count on the returned object of your query.

On accessing the properties on an anonymous type collection, that can only be done by using a foreach...

Answer 5

What I really want is count(*) but I don't know how to do that in Linq. The way I have it now seems to give me the correct count.

Answer 6

Ok I didn't know about tuple and that is what I want I think. Can you help with syntax in Linq?

I tried

 

 var query = (from disposition in db.DispositionHolds
               group disposition by new

               {
                 disposition.ReportDate,
                 disposition.FileName
               } into d
               select new Tuple<int, string,string>(
               {
                 count = d.Key.FileName.Count(),
                 d.Key.ReportDate,
                 d.Key.FileName
               }));
        return (Tuple)query;

 

Answer 7

As I said do you want the ammount of records pulled from the query?

Answer 8

Yes. Here is the original SQL

 

SELECT COUNT(*)AS Count, ReportDate, FileName
FROM dbo.DispositionHold
GROUP BY ReportDate, FileName

Answer 9

var query =

from d in DispositionHold

group d by new{ d.ReportDate, d.FileName} into g

select new

{

ReportDate = g.Key.ReportDate,

FileName = g.Key.FileName,

Count = g.Count()

};

Answer 10

var query =

from d in DispositionHold

group d by new{ d.ReportDate, d.FileName} into g

select new

{

ReportDate = g.Key.ReportDate,

FileName = g.Key.FileName,

Count = g.Count()

};

Thanks for the help with the count. Now I just need to return a tuple.

Answer 11

IQueryable<DispositionHoldCount> query =

from d in DispositionHold

group d by new{ d.ReportDate, d.FileName} into g

select new DispositionHoldCount

{

ReportDate = g.Key.ReportDate,

FileName = g.Key.FileName,

Count = g.Count()

};

Create a class somethingl ike this:

class DispositionHoldCount
{
public string ReportDate { get; set; }
public string FileName { get; set; }
public int Count { get; set; }
	
}

then use that into the query

 

Answer 12

IQueryable<DispositionHoldCount> query =



from d in DispositionHold



group d by new{ d.ReportDate, d.FileName} into g



select new DispositionHoldCount



{



ReportDate = g.Key.ReportDate,



FileName = g.Key.FileName,



Count = g.Count()



};

Create a class somethingl ike this:

class DispositionHoldCount

{

public string ReportDate { get; set; }

public string FileName { get; set; }

public int Count { get; set; }

	

}

then use that into the query

 

Yeah I can create a class but that seems overkill just to return rows of 3 fields.

Answer 13

var query =

from d in DispositionHold

group d by new{ d.ReportDate, d.FileName} into g

select new Tuple.Create(g.Key.ReportDate, g.Key.FileName,g.Count())


I assume reportdate is datetime, filename is string, etc

Answer 14

Well I go this far but got Create is a method but used as a type.

 

 var query = (from disposition in db.DispositionHolds
               group disposition by new

               {
                 disposition.ReportDate,
                 disposition.FileName
               } into d
               select new Tuple.Create<int, string, string>(d.Count(), d.Key.ReportDate, d.Key.FileName)
               {
                 Count = d.Key.FileName.Count(),
                 ReportDate = d.Key.ReportDate,
                 FileName = d.Key.FileName
               });
        return query;

Answer 15

var query = (from disposition in db.DispositionHolds
               group disposition by new

               {
                 disposition.ReportDate,
                 disposition.FileName
               } into d
               select new Tuple<int, string, string>(d.Count(), d.Key.ReportDate, d.Key.FileName);

http://msdn.microsoft.com/en-us/library/dd386921.aspx

Read this
              

Answer 16

var query = (from disposition in db.DispositionHolds
               group disposition by new

               {
                 disposition.ReportDate,
                 disposition.FileName
               } into d
               select new Tuple<int, string, string>(d.Count(), d.Key.ReportDate, d.Key.FileName);

http://msdn.microsoft.com/en-us/library/dd386921.aspx

Read this
              

Thanks that works.