How to handle database connection in ASP.NET MVC 4 gracefully?

Question

How do I gracefully handle errors when trying to connect to a database that may be down, or given an incorrect connection string in MVC 4?

I have my string in Web.config and the way it accesses the database is just instantiating my class derived from DBContext in each controller, like so:

private DBEntities db = new DBEntities("database");

This works fine if the database is up and everything is correct, but if it's not, the pages on my web site display this error:

Exception Details: System.ComponentModel.Win32Exception: The network path was not found

Obviously I don't want this to appear, what I'd like to do is have a way to try catch the error and display a custom error page (similar to 404 Page Not Found).

Thank you.

CR41G14 · Accepted Answer · 2012-12-04 14:15:16Z

1

Do the initialisation in the function

private DBEntities db;

// then in your function attempt to initialise
try{

db = new DBEntities("database");

db.Connection.Open();

}
catch(Exception ex){

if(db.Connection != ConnectionState.Closed){

db.Connection.Close();
db.Dispose();

//go to error page
}

}

answered Dec 4, 2012 at 14:15

CR41G14

5,6245 gold badges47 silver badges68 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Paul D'Ambra · Accepted Answer · 2012-12-04 14:14:16Z

1

It depends where private DBEntities db = new DBEntities("database"); is and when it is called but why not just:

try {
  private DBEntities db = new DBEntities("database");
} catch (Exception ex) {
  //do something here
}

answered Dec 4, 2012 at 14:14

Paul D'Ambra

7,8243 gold badges57 silver badges98 bronze badges

2 Comments

swiftcode Over a year ago

Yes, that seems good but I have one line of that per controller, so I think it's best to place that code in a function somewhere and instantiate it when needed.

Paul D'Ambra Over a year ago

Ah, definitely look into injecting an interface into your controllers rather than instantiating your DBEntities in the controllers themselves. I use Ninject but there're many, many more to choose from...

paul · Accepted Answer · 2012-12-04 14:21:21Z

1

start by adding an 'Error.cshtml' view in the Shared views folder. Give it a model type of System.Web.Mvc.HandleErrorInfo

Then add the following to your web.config file

<system.web>
  <customErrors mode="On" defaultRedirect="/Error" />
</system.web>

This will redirect to the Error view on any exception.

Now it's just a matter of styling your error page.

I'd advise you try { } catch { } as suggested in the other posts, in your catch block, just rethrow with a user-friendlier message - like "Database connection could not be made."

Quite a full discussion/explanation here: http://www.prideparrot.com/blog/archive/2012/5/exception_handling_in_asp_net_mvc

answered Dec 4, 2012 at 14:21

paul

22.1k1 gold badge56 silver badges54 bronze badges

Collectives™ on Stack Overflow

How to handle database connection in ASP.NET MVC 4 gracefully?

3 Answers 3

Comments

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related