Invoke a C# method from inside a SQL trigger

I am into a Winforms application using C# and Visual Studio 2010 along with SQL Server Management Studio 2008 R2.

My application checks the previous values in the database and if the current val开发者_如何学Pythonue being inserted falls under a certain range, I need to execute a method written in C# i.e. the host language. The method actually sends E-mails to the e-mail addresses stored in the database.

Now the checking part can be easily done using a trigger but the latter is troublesome for me.

Can anyone please help me out?

There are a couple of ways to handle this.

1. You could log an entry to a database that a C# service watches, and when an entry is added, it sends e-mails. This could be some sort of a Windows Service that runs on a Timer every 1 minute checking for updates.
2. You can use the SQL-CLR to integrate C# code with SQL code. This requires opening a few security points and embedding the binary files from your project into SQL Server. This is a less preferred method for security reasons, but it can do the job.

You might want to look into Database Mail. This integrates email sending functionality within SQL Server.

Otherwise, I'd strongly suggest not trying to do this directly within the trigger - sending an email could be a time consuming process, and you wouldn't want to delay the completion of the transaction if the email functionality isn't currently working.