AsNoTracking using LINQ Query syntax instead of Method syntax

Question

I'm interested in using AsNoTracking with my LINQ select queries to improve performance. I'm using Entity Framework 5 with Code First.

However, all of my queries are written using LINQ Query syntax and all of the AsNoTracking examples are shown using the Method syntax. I'm aware that AsNoTracking was created for the Method syntax but how do I achieve the same thing with the Query syntax?

AsNoTracking does NOT improve performance, because it lets EF contact the datasource on each call. Tracking is therefore also caching and improves performance. — Rob
– Rob, Commented Aug 8, 2013 at 9:45
Hi Robert, that's interesting because I've read a lot of articles that point towards AsNoTracking() giving a performance improvement when using SELECT's without needing to do any updating. ie blog.staticvoid.co.nz/2012/4/2/… — Mitch
– Mitch, Commented Aug 8, 2013 at 9:55
Ok, to be precise: AsNoTracking is indeed faster when fetching data that has not been fetched before, because it does not need to check if the desired data is already present (which would be the fastest, of course). — Rob
– Rob, Commented Aug 8, 2013 at 10:00

qujck · Accepted Answer · 2013-08-08 12:08:48Z

33

You apply AsNoTracking() to the DbSet:

var result = (
    from person in ctx.People.AsNoTracking()
    select person)
    .ToList();

answered Aug 8, 2013 at 12:08

qujck

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5 Comments

Chris Over a year ago

Works but I had to add using Microsoft.EntityFrameworkCore;

Adrian Over a year ago

what about joins? Do you apply them to those sets as well? EG:

from s in _context.Strategy.AsNoTracking() join sv in _context.StrategyVersion.AsNoTracking() on s.Id equals sv.StrategyId

qujck Over a year ago

See this answer

Hooch Feb 20 at 14:17

Do I need to add this to DbSets tat I include in joins?

qujck Feb 20 at 15:21

@Hooch ^^ it's literally the comment above yours

MarcinJuraszek · Accepted Answer · 2013-08-08 09:45:09Z

1

Query syntax is replaced with method syntax by compiler, so there is no difference at all at the end.

answered Aug 8, 2013 at 9:45

MarcinJuraszek

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2 Comments

Mitch Over a year ago

I've tried using AsNoTracking() with my Query syntax but it doesn't even show up on Intellisense as an option.

Mitch Over a year ago

On further thoughts, maybe I'm not using it correctly or I'm missing a library? ie var result = (from person in ctx.People select person).AsNoTracking().ToList()

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