How can I grab two columns from a table in LINQ?

Question

I've got this code:

            MobileServiceTableQuery<String> query =
                table.Where(i => i.PlatypusID == platypusID).
                      Where(i => i.Id > lastIDToIgnore).
                      Select(i => i.DuckbillName);

...which works, but what if I need to select two columns? The two "guesses" I had (below) don't compile:

. . .
                      Select(i => i.DuckbillName).
                      Select(i => i.Swamp);

. . .
                      Select(i => i.DuckbillName, i.Swamp);

Answer 1

Hi,

First the Select() in your linq query is not meant for selecting multiple columns. Please refer this link.

Also the MobileServiceTableQuery<String> can be used to a list of strings and not a list of <String, String>.

You can change your query something like this.

var query = from tbl in yourTable
		where  tbl.PlatypusID == yourPlatypusID 
		       && tbl.Id > lastIDToIgnore
             select new
                     {
                         tbl.DuckbillName,
                         tbl.Swamp
                     };

---

Microsoft MVP - ASP/ASP.NET

Answer 2

Ramesh's post completely answers your questions and also I want to suggest you watch this videos

http://www.asp.net/web-forms/videos/data-access/how-do-i-with-linq/how-do-i-linq-to-sql-overview

It's very helpfull and easy to understand videos for beginners in LINQ, you'll learn a lot from this.

---

Please Mark as Reply and Vote as Helpful if I helped.

Also please visit my blog http://msguy.net/

Answer 3

Hi,

First the Select() in your linq query is not meant for selecting multiple columns. Please refer this link.

Also the MobileServiceTableQuery<String> can be used to a list of strings and not a list of <String, String>.

You can change your query something like this.

var query = from tbl in yourTable
		where  tbl.PlatypusID == yourPlatypusID 
		       && tbl.Id > lastIDToIgnore
             select new
                     {
                         tbl.DuckbillName,
                         tbl.Swamp
                     };

---

Microsoft MVP - ASP/ASP.NET

When I try this:

             from tbl in table
             where tbl.SenderID == senderID
                   && tbl.Id > lastIDToIgnore
             select new
                     {
                         tbl.ReaderName,
                         tbl.SenderDeviceID
                     };

...I get, "Cannot implicitly convert type 'Microsoft.WindowsAzure.MobileServices.MobileServiceTableQuery<AnonymousType#1>' to 'Microsoft.WindowsAzure.MobileServices.MobileServiceTableQuery<TaSLS_PhoneApp.TaSLs_Data.TASLS_WAMS_INVITATIONS>'"