VB.NET - LINQ to SQL - How do I add in Row_Number to a LINQ to SQL query in VB.NET?

Question

How do I add ROW_NUMBER to a LINQ query or Entity?

How can I convert this solution to VB.NET?

var start = page * rowsPerPage;
Products.OrderByDescending(u => u.Sales.Count())
    .Skip(start)
    .Take(rowsPerPage)
    .AsEnumerable()
    .Select((u, index) => new { Product = u, Index = index + start }); // this line gets me

I'm having trouble porting that last line. I have been unable to locate a VB.NET example.

I'm actually not looking for any paging functionality like the example provides, just good old-fashioned Row_Number(Order By X) row index.

What is the purpose of the OrderByDescending(u => u.Sales.Count()) in this example? Since the count doesn't change during the query, this effectively does nothing other than spin cycles (assuming SQL doesn't optimize it out of the execution plan). — Jim Wooley, Sep 01 '11 at 14:26
I don't know. This is a code snippet from another Stackoverflow post. I'm interested in projecting a row index into the list of anon objects in VB.NET — Brian Webster, Sep 01 '11 at 15:43
In that case, use the overload in Select David B mentioned below. — Jim Wooley, Sep 01 '11 at 17:18

score 6 · Accepted Answer · edited Oct 15 '14 at 19:20

LinqToSql can't do a Row_Number(Order By X) in the database.

The c# code you posted does it against in-memory instances by calling Enumerable.Select

On the msdn page for Enumerable.Select, there's a vb.net example.

Here is a working example that demonstrates the projection of a row index in VB.NET:

Dim R = (
     From P In DB.Products Select P
  ).AsEnumerable().Select(
     Function(Product, index) New With {index, Product}
  )

Response.Write(R(12).Product.Doc_width.ToString()) 'Access object members
Response.Write(R(12).index.ToString() 'Access Row Index

VB.NET - LINQ to SQL - How do I add in Row_Number to a LINQ to SQL query in VB.NET?

1 Answers1

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