Question

public long GetNewCRN()
{
   return ((from c in DataContext.GetTable<Cust_Master>() 
            select c.CUSTSERH_CRN).Max() + 1);
}

Will this Linq to Sql query fetch all records from the table first and then select the maximum of the column ?

If yes, then isn’t it a bad idea using linq to sql instead of normal SqlCommand ?

Or is there any other way of doing it in linq to sql ?

---

When I attach Console.Out, I see nothing(command prompt does not even open).

But when I include following:-

context.Log = new System.IO.StreamWriter("d:\\abcd.txt");

I get an error, that “The process can not access the file because it is being used by another process” and that process is “w3wp.exe”.

How can I see the sql commands being executed by DataContext then ?

Answer 1

No this shouldn’t fetch all rows. You are only requesting the maximum value. This should be converted to an SQL query like the following:

SELECT MAX(CUSTSERH_CRN) FROM Cust_Master

You can verify that this is the case by attaching a logger to the DataContext before you execute the command, for example:

DataContext.Log = Console.Out;