Tag: RavenDB

During the week at work we came across an issue where we are doing a linq query which is using a statement such as this:-
[sourcecode language=”csharp”] var product = session.Query().Single(GetSource(key));
[/sourcecode]

In Sql Server land we have a product table and the field productcode is unique – we noticed that in RavenDB we were seeing products
which had the same productcode in different documents (not unique), this was not the desired outcome and so we looked into how to go about fixing this in RavenDB, enter the uniqueconstraints RavenDB bundle.

RavendDB bundles are like add-ons and Raven comes with quite a few and they can be exceptionally handy. To use the uniqueconstraints bundle you create a folder and call it plugins, usually you keep this inside the server folder but you can put it anywhere and add a config value so that Raven can find your plugins, an example of how to set up your config to locate plugins:-

[sourcecode language=”xml”] <?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appSettings>
<add key="Raven/Port" value="*"/>
<add key="Raven/DataDir" value="c:\RavenDB\Data"/>
<add key="Raven/IndexStoragePath" value="c:\RavenDB\Data\Indexes" />
<add key="Raven/Esent/LogsPath" value="c:\RavenDB\Data\Logs" />
<add key="Raven/PluginsDirectory" value="c:\RavenDB\Plugins"/>
<add key="Raven/AnonymousAccess" value="All"/>
<add key="Raven/ResetIndexOnUncleanShutdown" value="true"/>
</appSettings>
<runtime>
<loadFromRemoteSources enabled="true"/>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<probing privatePath="Analyzers"/>
</assemblyBinding>
</runtime>
</configuration>
[/sourcecode]

Server side checking

• To to use the uniqeconstraints bundle add the Raven.Bundles.UniqueConstraints.dll from the bundles folder to your plugins folder where ever you decide to put them.
• Then restart RavenDB
• To see if they have been installed and picked up – go to the Raven Management Studio and then at the bottom left hand side, click on statistics – next to where it says Triggers it should say something like Raven.Bundles.UniqueConstraints.UniqueConstraintsDeleteTrigger

Client Side checking

In order to implement the check through code we borrowed the example written by Richard Dingwall taken from his blog.

[sourcecode language=”csharp”] namespace WhateverNameSpaceYouHave.Extensions.RavenUniqueConstraint
{
using System;
using System.Linq.Expressions;

using Raven.Client;

public interface IRavenUniqueInserter
{
void StoreUnique(IDocumentSession session, T entity, Expression<Func<T, UTunique>>; keyProperty);
}
}
[/sourcecode]

Aboove the interface, below that code that uses it:-

[sourcecode language=”csharp”] namespace WhateverNameSpaceYouHave.Extensions.RavenUniqueConstraint
{
using System;
using System.Linq.Expressions;

using Raven.Abstractions.Exceptions;
using Raven.Client;

public class RavenUniqueInserter : IRavenUniqueInserter
{
public void StoreUnique(IDocumentSession session, T entity, Expression<Func<T, Tunique>> keyProperty)
{
if (session == null)
{
throw new ArgumentNullException("session");
}

if (keyProperty == null)
{
throw new ArgumentNullException("keyProperty");
}

if (entity == null)
{
throw new ArgumentNullException("entity");
}

var key = keyProperty.Compile().Invoke(entity).ToString();

var constraint = new UniqueConstraint { Type = typeof(T).Name, Key = key };

DoStore(session, entity, constraint);
}

private static void DoStore(IDocumentSession session, T entity, UniqueConstraint constraint)
{
var previousSetting = session.Advanced.UseOptimisticConcurrency;

try
{
session.Advanced.UseOptimisticConcurrency = true;
session.Store(constraint, string.Format("UniqueConstraints/{0}/{1}", constraint.Type, constraint.Key));
session.Store(entity);
session.SaveChanges();
}
catch (ConcurrencyException)
{
// rollback changes so we can keep using the session
session.Advanced.Evict(entity);
session.Advanced.Evict(constraint);
throw;
}
finally
{
session.Advanced.UseOptimisticConcurrency = previousSetting;
}
}
}
}
[/sourcecode]

How to call it from code
[sourcecode language=”csharp”] try
{
new RavenUniqueInserter().StoreUnique(session, destination, x =&gt; x.Code);
LogManager.GetCurrent().Event(LoggingLevel.Info, "Inserting Product:+" + destination.Code, "Method name here");
}
catch (ConcurrencyException)
{
LogManager.GetCurrent().Event(
LoggingLevel.Error,
"Product code already in use. Code: " + destination.Code, "Method name here");
}
[/sourcecode]

And thats it, now we wont be able to add a product with a productcode which already exists in our RavenDB database, making it a unique constraint just as youd have in Sql.

Please add a comment or ask a question if you found this useful.

I was wondering how I would go above upgrading from one build version of RavenDB (build 701) to a newer version of RavenDB (build 888) and decided to find out how.

As it turns out like most things in RavenDB its very easy! – the following is how to go about upgrading from one version of RavenDB to another.

Note:- You can do it this way and this is the recomended way here however I wanted to try doing it using importing and exporting the data.

Please not that this was done on my local dev machine at work and not done in a production environment, it wont cover replication as well as some other things to think about but its covers the basics.

I have RavenDB build 701 running from d:\ravedb-build\701 which runs on http://localhost:8080, I then added some test documents to the default database.

I noticed RavenDB had been updated to Build 888 and I began to think how do I get the data out of the old build version and into the new version, having a quick look I soon realised that I need to export data from the 701 build and then import that data into the 888 build.

Here is how I went about it:-

1. I have RavenDB build 701 running from c:\ravendb\RavenDB-Build-701\ and had 50 documents within it – this runs from http://localhost:8080 as seen below:-
2. I then downloaded RavenDB build 888 and ran that from d:\RavenDB-Build-888\ which was empty – this runs from http://localhost:8082 as seen below:-
3. Now we can see the differences in the document database as below, Raven 701 build with documents:-
   
4. And the Raven 888 build with no documents as yet:-
   
5. To export and import data within RavenDB you use a tool called smuggler, smuggler can be found within the Smuggler folder and the exe is called Raven.Smuggler.exe
6. To export the data from RavenDB Build 700 I went into a command prompt window moved into the location of the smuggler exe and ran the following command -> Raven.Smuggler out http://localhost:8080 dump.raven
   
7. Ok great, now we have exported our data, time to import it into the newer 888 build of RavenDB, to do this we need to a couple of things, firstly locate the dump.raven file in the 701 build/smuggler folder as below:-

   

   And then copy it to somewhere for importing, to make it easy I just copied it to the smuggler folder within the build 888 as below:-

   

   Then go to the smuggler folder for this build and then use the following command -> Raven.Smuggler in http://localhost:8082 dump.raven

8. We will see Raven ha imported our documents for us:-
9. Lastly lets check in the new build 888 that our documents are there:-
   

And there we go we have moved out documetns from the 701 build to the 888 build, if yo do this you will notice that the index definitions are copied there but havent been built, i.e. youll need to rubuild them manually.

Please feel free to leave a comment if you find this useful or have any questions.

I have seen a few people ask how to go about accessing the RavenDB studio when they use RavenDB in embedded mode, normally you would tend to use embedded mode when unit testing.

In the following article I show you how to get the RavenDB Management Studio working in an MVC 3 application.

1. File, New, MVC 3 Application as below:-
2. Choose whatever you prefer in the next window, I chose Internet Application:-
3. Now using Nuget add in the RavenDB Embedded package:-
4. Now we need to add in some details for the application to talk to RavenDB, lets do that now, so edit the global.asax.cs file to have the following code:- [sourcecode language=”csharp”] public static IDocumentStore Store { get; set; }

   public static void RegisterGlobalFilters(GlobalFilterCollection filters)
   {
   filters.Add(new HandleErrorAttribute());
   }

   public static void RegisterRoutes(RouteCollection routes)
   {
   routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

   routes.MapRoute(
   "Default", // Route name
   "{controller}/{action}/{id}", // URL with parameters
   new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults
   );
   }

   protected void Application_Start()
   {
   AreaRegistration.RegisterAllAreas();
   RegisterGlobalFilters(GlobalFilters.Filters);
   RegisterRoutes(RouteTable.Routes);

   Store = new EmbeddableDocumentStore {
   DataDirectory = "Data",
   UseEmbeddedHttpServer = true
   };
   Store.Initialize();
   }
   [/sourcecode]

5. Now in order to be able to view the RavenDB Management Studio we need to locate the file Raven.Studio.xap from the packages folder which was created when we added in the Nuget package above.

   The packages folder is located in the directory above the folder in which your solution currently resides, once you locate the packages folder locate the RavenDB-Embedded(version number) folder in my case this is RavenDB-Embedded.1.0.701 – the file we are looking for is in the packages\RavenDB-Embedded.1.0.701\lib\net40\

   Copy the Raven.Studio.xap to the root of your website and now try running your MVC website.

6. Once that loads up now browse to http://localhost:8080 and the RavenDB Studio should load up – and that’s you.
7. If you see this:-

   It means you havent copied the Raven.Studio.xap to the root of your website.

I hope this helps someone out.

Your application is starting to take shape and you want to be able to quickly see what’s going on when using RavenDB.

Step forward the in-built profiling dll which is very easy to set up and get going with, lets implement that along with MiniProfiler.

1. Add the Nuget package MiniProfiler.RavenDb to your application
2. Add the Raven.Client.MvcIntegration dll which can be found in the Client folder when you download the source for RavenDB
3. Add the following to your global.asa.cs file:-
   [sourcecode language=”csharp”] protected void Application_BeginRequest()
   {
   if (Request.IsLocal)
   {
   MiniProfiler.Start();
   }
   }
   [/sourcecode]

   and then :-

   [sourcecode language=”csharp”] protected void Application_EndRequest()
   {
   MiniProfiler.Stop();
   }
   [/sourcecode]
4. Add the following to your global.asa.cs file in the Application_Start event:- [sourcecode language=”csharp”] Raven.Client.MvcIntegration.RavenProfiler.InitializeFor(Store);
   MvcMiniProfiler.RavenDb.Profiler.AttachTo((DocumentStore)Store);
   [/sourcecode]
5. Lastly add the following lines into your _Layout.cshtml file in the Shared folder, under Views:- [sourcecode language=”csharp”] @MvcMiniProfiler.MiniProfiler.RenderIncludes()
   @Raven.Client.MvcIntegration.RavenProfiler.CurrentRequestSessions()
   [/sourcecode]

That’s it – you have now adedd the built in profiler and MiniProfiler for RavenDB, run your application and you can
see that in the top left hand corner you can view the details of whats going on in both profilers:-

MiniProfiler for RavenDB looks like this:-

and this:-

while with the RavenDB profiler we see something like this:-

The in-built profiler from RavenDB shows us how long the query took, the status, result, Method, Url, Query and Actions as well as the actual request details.

All in all both profilers are very hand and very easy to install – go get them installed.

Here is a list of hints and tips if you’re looking for some help with RavenDB.

• Sign up for the mailing list where you can see other people’s previous questions and answers to problems on the View the Google Group.
• To make sure RavenDB doesn’t clash with routing used in MVC change the global.asa.cs file from:-

  {controller}/{action}/{id} to {controller}/{action}/{*id} – Note the * next to the {id} or you can do this.

• If I choose the Embedded version of RavenDB how do I start the server – to start the RavenDB server locate the RavenDB folder and then look for the server folder and then run Raven.Server.Exe
• If I install RavenDB using Nuget then what do I do, locate the packages folder which is in the folder one above the solution you’ve added it to on the file system, locate the RavenDB folder and then look for the server folder and then run Raven.Server.Exe
• How do you view the RavenDB Studio – easiest way is to browse to http://localhost:8080, that’s the default location of installation when you first run the Raven.Server.Exe
• Unit testing – how best to go about it – the recommended way to go about this is by using the EmbeddedDocumentStore
  which is basically all done in memory, you can set it up like this:-
  [sourcecode language=”csharp”] var documentStore = new EmbeddableDocumentStore
  {
  DataDirectory = "Data",
  RunInMemory = true,
  UseEmbeddedHttpServer = true
  };
  [/sourcecode]
• Good RavenDB Samples RavenOverFlow and Racoon Blog

If your stuck with something give me a shout I’ll see if I can shed some light, I’ll be adding more tips as I learn more RavenDB.