I'm looking to write a scaled out SignalR application using SQL Server, using this article as a guidline. After doing some testing, it looks like the table Messages_0 in the SignalR database that I created (per the article) could get pretty big.
What I'm wondering is, how often can this data be cleared out? I see there is an InsertedOn column so I would think after day or two the data wouldn't be relevant anymore. Is there any documentation or guidelines on this?
I'm wondering if I could just set up a job that would clear out anything older than a week just to prevent the table from getting too big over time.
I was looking for the same thing, and I did read the suggestion in the documentation, but I was wondering if SignalR would clean up by itself in that case, and when.
I found the answer here: How to cleanup SignalR SQL database
Which points to the github repository, where you can see how SignalR automatically cleans the tables when reaching a hardcoded limit.
See github code here: SignalR SQL automatical clean-up
Thought it might be useful to add to this question, for anyone searching the same question.
The documentation seems to suggest (albeit briefly), that you should not delete rows yourself.
SignalR manages the tables. As long as your application is deployed, don't delete rows, modify the table, and so forth.
Take a look at: Scaleout With SignalR - asp.net
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I have a flask app that is deployed on Google's App Engine. I have noticed a minor bug and I would like to fix it but my database is already populated.
How can I make this minor code change and push / deploy back to my app without losing all my data? (which is probably a basic question but I'm not finding much. all tutorials online are focused on creating the app and deploy, not updating)
Thus far, I have been dropping and re-creating the tables whenever I redeploy, mostly out of ignorance. Here are the steps I have followed
1). make the change in my app
commit and push changes to bitbucket source code
in Google Cloud SDK: git pull
Google Cloud SDK: gcloud app deploy
These steps result in an empty database because the directory I am pushing from my local computer has an empty database. Is this where I should be using git merge?
Is this a database "migration" or is this a "git merge"? I'm not sure what the right terms are to use to research this further. Thanks.
There are a couple of angles to your question. I'm going to try to give you some information, but let me warn you, this isn't going to be a trivial change to your workflow, you'll have to change some things.
First of all, based on the way you worded your question I get the idea that you commit your database to git along with your code. If I got this right, then this is something that you need to stop doing. The database is not code, so it should not be committed to source control.
You should have a completely independent database on each installation of your application. For example, you will have a database on your own machine to do development. You will also need another database in your gcloud deployment. You may need more databases if you have other uses for your application. A very common third database for many people is one that is used for automated tests, which could also be located in your local development machine, but is not the same database that you use for day to day development.
To make changes to your database schema you will not drop and recreate tables anymore, that is clearly something that you already realized that needs an improvement. A good approach to make these changes is to use a database migration framework. These tools allow you to generate short scripts that make these changes to the database in a more focused way, without destroying and recreating everything, and for that reason, the data is in general not lost. For Flask-SQLAlchemy, the best option for database migrations is Flask-Migrate, which is a lightweight wrapper around the Alembic migration framework. (I might be biased here as I'm the author of the Flask-Migrate extension!).
Documentation for Flask-Migrate: https://flask-migrate.readthedocs.io/en/latest/.
My current development environment for C# projects is Visual Studio, with a SQL Server database and using VisualSVN to connect to my SVN repository. To manage revisions of my Stored Proceduress, Views, etc I save the ALTER script to a folder watched by my SVN client so these get included in the repository.
I have checked out some (now older) posts like this one (How to keep Stored Procedures and other scripts in SVN/Other repository? and Is there a SVN plugin for SQL Server Management Studio 2005 or 2008?) and have seen a recommendation for these tools: http://www.red-gate.com/products/sql-development/sql-source-control/ and http://www.zeusedit.com/agent/ssms/ms_ssms.html .
As I infrequently work with projects doing much DB-side programming, this has never been a major bother (a dozen scripts in a folder with some naming scheme is not much to manage manually), but I have just inherited a project with a few hundred views and 1000+ Stored Procedures which have never been included in version control.
My question is:
What process do others follow for managing the versioning of their SQL Server code - is there a an accepted, clever or otherwise obvious approach I am missing here? I am leaning currently towards the purchase of one of the aforementioned tools - but am looking for advice from the community before I do this.
I realize this may result in a tool recommendation rather than a code solution but posted to SO as I think this is the appropriate crowd to ask this of.
I would recommend you go with something like the redgate tool, and treat any SQL database in the same way you'd treat your C# source code; manually keeping track of the ALTER statements will trip you up sonner or later as the number of modifications grow..can't speak for the zeus edit tool but having used the redgate one, it "just works" - and another benefit of using a tool like this is that it can manage your migration scripts so you can make a bunch of changes on your development version, then generate a single update script to update your testing database, etc,including data changes which is imho the biggest PITA to manually manage.
The other thing to consider, even if the number of changes are infrequent and you get away with manually tracking the ALTER statements, what if someone else ends up working on the same project; now you have another potential for mismanaged change scripts....
Anyway, do let us know how you get on and best of luck with it!
I’ve been maintaining a database with around 800+ db objects in it. We've always just scripted the database objects to a svn-watched folder as you describe. We have had some issues with this method, mostly with people forgetting to script new or modified objects. At the end of the day it hasn't been a huge problem for our project, but yours may be different.
We’ve looked into a couple tools, but they always assume you are starting from scratch, and we have almost 10 years of history we’d like to preserve. In the end we just end up settling back into our text-based manual solution. It's cheap and easy.
Another option you might want to look into is setting up a Visual Studio Database Project. It will script all your objects and provide some deployment options as well. My opinion was that it tired to be a little too tightly integrated for our tastes - we have a few named references to linked databases that it just wouldn't give up on.
I am currently investigating possible options of a migration framework/tool. I like the idea of ruby migrations on which the above frameworks are based.
So I am asking for your experience, opinions and maybe a comparison between them. Are you using them in production?
thanks for responses. The goal of this question was to get a feeling about which tools is used most in the developer community but it seems that migrations are not a hot topic here.
Anyway, I have decided to go with MigSharp as the codebase seem to be pretty clean and it is quite easy to handle and had build in support for MS SQL CE. Second runner up would have been FluentMigrator where I was not able to produce a working example for compact edition.
Cheers
I use FluentMigrator in production, and am a longtime contributor to FM. I think your question is to general; be more specific. Also, FM has a google group which is fairly active if you want FM information.
FM is derived from migrator.net, as I recall. It uses a fluent-syntax, and supports multiple databases. We have taken some inspiration from rails migrations, but it's definitely not a port. Worth checking out.
One thing I've learned is not to put your migrations in the same assembly as you app code. Separate them into a migration assembly, and use that for migrating your databases.
Also, you should always work on multiple environments to avoid problems with migrations run straight against production. I always have at least a development and production environment, and most of the time there is a testing environment as well.
I use mig#.
It works well, but you will need to have some guidelines for usage - as migrations can get complicated.
We use sequence number on the end of our migrations rather than a date-time stamp. This is because we don't know when the date time stamp was set (when they begun the source code change-set; just before committing; some time inbetween) different developers could use different approaches.
Names such as Migration_0000034.cs give you plenty of space.
At this point, I would stick with migrator.net. I like the promise of FluentMigrator, but it seems to not have any better active development than migrator.net (see the issues and pull requests that have languished on their github site).
There is also no easy way to do an ExecuteScalar(). I'd add it, but I don't want to create my own fork, and I see no reason that a pull request would actually land in the master. (Execute.WithConnection is an Action so it will fire on demand rather than when I need it to fire)
So for me, I'm heading back to migrator.net.
I am working on an in-house, iOS app that will need read-only access to a SQL Server with multiple databases. I know the stock answer here is "write some web services", but I'd like a solution that is self-contained. Is there any way to directly connect to a SQL Server database from an iOS application? I'm thinking something like a basic ODBC connection.
I've seen a lot of users asking this question, but very few answers other than "write a web service." Is that really the only way?
A web service is indeed the only way, but Red Gate's written one you can reuse:
http://www.mobilefoo.com/iSqlServerSDK.html
http://labs.red-gate.com/Tools/Details/iSqlSDK
It's not officially released yet, just in beta, so keep in mind that features & prices may change.
Actually the easiest way is to create a MVC 3 or 4 asp.net web application. call the web methods. You don't need any API to pay for.
I use SBJson to serialize domain object and then send the objects as serialized jSOn to MVC 3. It's super easy to do. I even send images with base64, so it's .net compatible.
See my blog post with sample code:
http://nickturner.wordpress.com/2012/10/09/107/
So, after much searching and trial and error, unfortunately the best (only?) way I've found is indeed using Web Services.
Fortunately, Linq to SQL makes the WCF-creation-side incredibly easy. Once I got someone at work to walk me through setting up a Windows web server and adding the web service (and buying access to an online web server), the Windows side was up and ready to go.
I'm still working through all of the syntax stuff on the SOAP interaction side, but keeping my different methods somewhat similar in structure allows me to tinker a little until it works. By this time, I think I've gotten it to work pretty well.
So, both answers I got back were (disappointingly) correct. The only way to interact is through a Web Service. Even the 3rd party solutions they mentioned were really just convenient wrappers around the same type of technology. As it turns out, I'd rather have finer control over the process.
One word of advice: Get a real, external web server. I tried doing this on a non-Server Windows VM on my iMac/MacBook Pro, and it was like pulling teeth! Once I actually got access to an external, full, stand-alone web server, the process was much more streamlined and easy. Do yourself a favor and take that headache out of the equation!
There was a SQL ISAPI extension as part of SQLXML, but I think it has been deprecated: http://msdn.microsoft.com/en-us/library/aa226559%28v=SQL.80%29.aspx
This was effectively a pre-built, and relatively open, web service - so I'm not sure this counts as a direct connection.
You could also check out http://odbcrouter.com/Main
We are investigating using the Microsoft Mobile Sync Framework and I would like to put together a quick prototype. I am trying to pitch Mobile Sync Framework ofer another sync provider. I have zero experience with it so far, so I am looking for good examples of how to use it to sync backend relational database to SQL Server Compact database to enable working in an offline scenario. It would be very helpful to see a sample syncing solution with Oracle as the back end, but Sql Server should be fine to get an understanding.
Thanks,
Tom
Have you checked out Oracle Database Lite?
It includes a full sync solution for mobile devices, and is (obviously) compatible with an Oracle back end.
You can download it here:
http://www.oracle.com/technetwork/database/database-lite/downloads/index.html
The download includes full documentation and several source code examples.
see here: Sync Framework Resources Hope that thread helps
For an end to end solution for syncing between a mobile device and a server, have a look at the SyncComm project
Also this article from syncguru should give you a head start on writing your own provider for Oracle - it's quite straightforward to plug said provider into SyncComm - but I can if needs be provide further guidance.