Question

Currently I update a single item in a database as follows:

 var master = (from tmi in db._Masters where tmi.Id == Id select tmi).FirstOrDefault();
 master.logPosition++;
 db.SubmitChanges();

This strikes me as inefficient, as (I think) I am pulling out a full DB row to just update a single value. Is there a more efficient query I can use?

Answer 1

You can select only the field you want to modify by adjusting your original linq select:

var master = (from tmi in db._Masters 
              where tmi.Id == Id 
              select new { tmi.logPosition }).FirstOrDefault(); 
 master.logPosition++; 
 db.SubmitChanges(); 

EDIT: By selecting the specific data into associated properties, the property logPosition should lose its read-only status and be fully updatable.

var master = (from tmi in db._Masters 
              where tmi.Id == Id 
              select new { 
                  ID = tmi.ID, 
                  logPosition = tmi.logPosition }).FirstOrDefault(); 
 master.logPosition++; 
 db.SubmitChanges();