LINQ Select First

Question

Hi I have this bit of linq code

var fp = lnq.attaches.First(a => a.sysid == sysid).name;

When profiled it generates the following t-sql

Answer 1

Project to the name property before using First():

var fp = lnq.attaches.Where(a => a.sysid == sysid)
                     .Select(a => a.name)
                     .First();

This doesn't change the use of an index though - for that your Where clause is responsible (in your initial query the lambda you passed to First()). Both queries benefit from an index on the name column, the second one is just faster because only one column value has to be materialized.