REturned Columns and Order by clause problem

Question

 

Hi Guys, I am starting to work with LINQ and found some problems that the reason can be my small knolegment about the tecnology, but, its strange.

 

Well, when I make the following query :

 

Code Snippet

dim x = From r in datacontext.table where r.name = "Test" select [date] = r.date.toShortDateString, r.Name

 

 

 

Until now, everything ok, but, when I add the Order by [date]. get the following messge.

 

Both DataSource and DataSourceID are defined on 'gvEvents'.  Remove one definition.

 

Another question is that, how can I set a alias for my columns with space ? Example:

 

Code Snippet

SQL - select name as 'My account'  , 'My address' = address from Table

 

LINQ - .....   select [My account] = name didnt work.

 

 

 

Tks a lot.

 

Thiago

Consultoria e Desenvolvimento de Soluções em Ti

Answer 1

I'm by no means a LINQ expert (I just started using it yesterday) but have you tried adding the following:

dim x = From r in datacontext.table where r.name = "Test" select [date] = r.date.toShortDateString, r.Name Into TestGroup = Group Order By [date]

The other thing you could try is giving your select fields aliases before doing the order by.  It would look like this I think:

dim x = From r in datacontext.table where r.name = "Test" select MyDate = r.date.toShortDateString, MyName = r.Name


I'm just learning this too so let me know if this works for you.

Answer 2

I don't think the name [date] is in scope in your order by and the VB compiler is generating some erroneous error message.  Of course, I'm guessing since you have not shown where the order-by clause is placed in your query.  The select clause you are using is constructing an anonymous type with two fields, one named '[date]' and the other named 'Name'.  You need something in scope that refers to the anonymous type instance before you can access the [date] field.  I'd suggest adding an into clause after the select but before the order-by.

 

dim x = From r in datacontext.table

            Where r.name = "Test"

            Select [date] = r.date.toShortDateString, r.Name Into x

            Order By x.[date]

 

 

 

 

 

Answer 3

 

The error looks like your gridview has been assigned a datasource in the aspx and in code. This is not a linq error / not linq related, but instead you need to remove either the designer datasource or the code that assigns a datasource...