CODEWITHSUNDEEP
c#asp.netasp.net-mvclinqentity-framework
Enrique Gil
Enrique Gil

Reputation: 754

The type arguments for method 'System.Linq.Queryable.SelectMany System.Linq.IQueryable

While editing my Repository class an Error pops out 

 var applicantList = (from a in context.Profiles
                             join app in context.APPLICANTs
                                on a.PROFILE_ID equals app.Profile_id into joined
                              from j in joined.DefaultIfEmpty()//.OrderBy(v => v.APPLICANT_ID)
                             select j //<--  this is APPLICANTs type
                               ).Take(1000);

   applicantdata = applicantList
                  .SelectMany(c => c.APPLICANTs) //this line added
                  .AsQueryable().OrderBy(v => v.APPLICANT_ID).ToList();

                if (applicantdata.Any())
                {
                    Cache.Set("applicants", applicantdata, 30);
                }
            }
            return applicantdata;

Im having an exception at 

.SelectMany(c => c.APPLICANTs) //this line added

saying that :

The type arguments for method 'System.Linq.Queryable.SelectMany(System.Linq.IQueryable, System.Linq.Expressions.Expression>>)' cannot be inferred from the usage. Try specifying the type arguments explicitly

Upvotes: 1

Views: 3768

Answers (2)

Christopher Stevenson
Christopher Stevenson

Reputation: 2861

SelectMany is used for 'flattening' a list of lists. You don't have a list of lists here. You have a list of anonymous joined rows.

It's a bit difficult to infer what you're querying for, but if you're looking to get the related rows (the APPLICANTs rows), you can use this:

var applicantList = (from a in context.Profiles
                     join app in context.APPLICANTs
                     on a.PROFILE_ID equals app.Profile_id
                     select app).Take(1000)

Upvotes: 1

Jahan Zinedine
Jahan Zinedine

Reputation: 14874

SelectMany accepts a collection of object which each of them have a collection property inside.

You selected APPLICANTs collection at the first statement and running a SelectMany on it doesn't seem to be meaningful.

Checkout these links to understand the SelectMany better.

http://msdn.microsoft.com/en-us/library/bb534336.aspx
Difference Between Select and SelectMany

Upvotes: 4

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