06 integrating extra features and looking forward

1. 06 | Integrating extra features and looking
forward
Christopher Harrison | Content Developer, Microsoft
Adam Tuliper | Technical Evangelist, Microsoft

2. Module Overview
• Stored procedures
• Increasing user experience with concurrency detection
• A few best practices
• Looking forward with Entity Framework 7

3. Stored procedures

4. Store procedures
• Why use stored procedures?
– Single point to secure – easier permissions
– Know exactly how DB is being queries
• Limits dynamic sql
– Still possible with sprocs, just more manual effort
• In general performance is _not_ a reason
– Virtually the same as sql query (pendulum swings both ways)

5. Stored procedures
• Support came in EF 6
– Only Fluent API based
• In the past could use procs manually
– var album = Database.SqlQuery<TriviaOption>("dbo.Proc….");
• Could map in the designer (which is going away)
• Code first will generate procedures for
– Insert, Delete, Update
• Wait – why no Select?

6. DEMODEMO
Integrating stored procedures

7. Increasing user experience with
concurrency detection

8. Concurrency
• As Christopher showed, easy to implement via concurrency token
– [TimeStamp]
– modelBuilder.Entity<YourEntity>()
.Property(e => e.Timestamp)
.IsRowVersion();
• Change detection can be enhanced via MVC Action Filters
• Let’s give the user the choice on how to proceed

9. DEMODEMO
Concurrency detection and user choice

10. A few best practices

11. Helpful hints in a web world
• Since the web layers (controller to view) are disconnected
– Always convert results to IEnumerable via .ToList()
• Ex. context.Albums.Where(o=>o.Title.Contains(search).ToList()
• Disable lazy loading in web environments
– context.Configuration.LazyLoadingEnabled = false;
– Use .Include to load related entities
– context.Albums.Include(o=>o.AlbumDetails)
• DbContext is not thread safe. Do not cache it!
– Always dispose DbContext when done

12. Context lifetime
• When context is gone, connection is gone
– Can’t (and shouldn’t) use connection from MVC view
– Get data, send to view
• Always execute result set when needed before exiting using()
using (var context = new MusicContext())
{
var albums = context.Albums
.Where(o=>o.Title.Contains(search))
.ToList());
return View(albums);
}

13. Watch out for…
• For complex joins, keep an eye on queries
– Remember context.Database.Log = s => Debug.WriteLine(s);
• Doing lots of inserts? AutoDetectChangesEnabled = false;
– EF detects changes on add to context and on save
– Can turn off and on again in same context lifetime
{
context.Configuration.AutoDetectChangesEnabled = false;
Do something
context.Configuration.AutoDetectChangesEnabled = true;
}

14. Async when appropriate
• EF supports async queries
– Async allows current thread to be used elsewhere
• Useful in case of network, db delays (long operations)
– Although not all the time, caution of overloading db
public async Task<ActionResult> Create(…)
{
if (ModelState.IsValid)
{
db.Albums.Add(album);
await db.SaveChangesAsync();
return RedirectToAction("Index");
}
return View(album);
}

15. Consider Connection resiliency
• This is a connection retry policy
• Works great with async
• Four modes
– DefaultExecutionStrategy
– DefaultSqlExecutionStrategy
– DbExecutionStrategy
– SqlAzureExecutionStrategy
• throws RetryLimitExceededException

16. DEMODEMO
Connection Resiliency & Async

17. Looking forward with Entity Framework 7

18. Notable new features
• Designer has been removed – Code First Only
• Rewritten from ground up with performance in mind
• New platforms
– Linux, OSX, Mono, Windows Phone*, Windows Store*
• New data stores
• In memory database
• Update-Database now split
– Apply-Migration
– Script-Migration

19. Resources
• Additional patterns
– http://www.asp.net/mvc/overview/older-versions/getting-started-with-
ef-5-using-mvc-4/implementing-the-repository-and-unit-of-work-
patterns-in-an-asp-net-mvc-application
• Reducing Code First Database Chatter
– http://romiller.com/2014/06/10/reducing-code-first-database-chatter/
• EF7 Project home
– https://github.com/aspnet/EntityFramework

20. ©2014 Microsoft Corporation. All rights reserved. Microsoft, Windows, Office, Azure, System Center, Dynamics and other product names are or may be registered trademarks and/or trademarks in the
U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft
must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after
the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.
©2014 Microsoft Corporation. All rights reserved. Microsoft, Windows, Office, Azure, System Center, Dynamics and other product names are or may be registered trademarks and/or trademarks in the
U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft
must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after
the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.