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How to automatically delete old records from sql server database?

I'm making a web application in aspnet, and I created a table in the database to insert notifications. I would like to know if there is any way to automatically delete data from this table that is older than 30 days. Is there any way this can be done?

Build a Stored Procedure with T-SQL that remove your older data than 30 days.
Assign procedure to SQL Server Agent.
Run server agent every day at specific hours.
With that way, your procedure will run every day and will delete your older data than 30 days according to the Procedure that you write.

I would like to know if there is any way to automatically
SQL Server build-in tool for schedule tasks (also called jobs) is the SQL Server Agent.
https://learn.microsoft.com/en-us/sql/ssms/agent/sql-server-agent
You can create a JOB which run a DELETE query
Note! I HIGHLY recommend NOT to delete data from the database in most cases! Disk are cheap and you will never know when the history information will be needed, but more important is simply that you should not have a reason for this in most cases. In big system you are using partitions and you can store the old data in separate file as well and there is no need to backup that file every time. In small system you can simply buy another cheap HDD disk if needed. Instead of DELETE rows you should design the system to mark the rows as logically deleted (for example add another column) if needed
Update: and what if we are using SQL Server Express?!?
SQL Server express does not support the use of the SQL Server Agent, which means that we need a different solution to schedule task, and the common solutions you can use are:
Solution 1: Using external scheduler
Disadvantage: This solution is in the Operating System level
If you are using SQL Server on windows, then you can Windows Task Scheduler: start menu -> search for "Task Scheduler" -> Right click "Task Scheduler" and select "Create Basic Task" -> fill the task information -> choose "Start a Program" as the action type and execute a ".bat" file which include sqlcmd command which execute your query
If you are using Linux then you can use Cron daemon - a system-managed executable that runs in memory in the background with which users may schedule tasks.
Solution 2: schedule tasks using SQL Server SERVICE (service broker); CONVERSATION TIMER; MESSAGE; CONTRACT; QUEUE
Note! This is my preferred option and I use it even when Agent is supported for many reasons! Service broker is super reliable, it's part of the SQL Engine, there is almost no overhead, it allows asynchronous and timed (repeated) execution at any time interval. With that said, it does not have access to the operating system like the SQL Agent does.
You can get a full sample including all the code to implement this solution in this post: https://www.sqlteam.com/articles/scheduling-jobs-in-sql-server-express-2

How to call restful service from SQL Server trigger

I need to call a restful web service with a single parameter from the insert event in a SQL Server database table. I know this is not ideal design but I don't have control of either end point. The usage of this functionality will not exceed 100 events/min at max load.
I'm open to other ideas but the two options I came up with were;
insert trigger - service broker - .NET windows service to call web service
C# CLR trigger to call restful service directly
I have been working on option 2 and created a SQL CLR trigger project in Visual Studio but after I add the references to System.Web the project will not build and there are no build errors, vs just says "build failed" in the output window.
Is there some restriction about which CLR libraries can be used in a CLR trigger?
Using the service broker scares me since I have only worked on one project with the service broker and found it very difficult to implement.
Any ideas on how to call the web service from the trigger event would be greatly appreciated.

A trigger is run in the context and scope of the statement that causes it to fire - this means, that statement isn't going to complete until the trigger is completely run.
A trigger should be very nimble - small and fast. You should never ever call external services from a trigger, you should not include cursors in triggers, you should not do any heavy lifting or lengthy calculations in a trigger.
If you really must do something like this, I'd recommend an approach that:
see the trigger just put a few values into a "Command" table - those values that the long-running process will need to complete its work
have a de-coupled, separate process (e.g. a stored procedure or something) that will check that "Command" table periodically for new tasks to complete - this can be done in SQL Server using a SQL Server Agent Job
the decoupled process then grabs the information from the "Command" table, does it's work, and updates the database (if necessary)
This way, your trigger is small and nimble and completes quickly, thus not slowing down your main process / main system. The lengthy process is decoupled, standalone, and can be implemented in whichever way makes most sense (stored procedure inside SQL Server, or a separate standalone e.g. command-line tool or whatever makes sense).

ASP.NET Update database every hour

I want to copy one row from table A to table B per hour on my asp.net website. How can I do that? Do I need win32 application? I would like to avoid that.

This sounds like you want to create a stored procedure and use the Sql Server Jobs scheduler to run it every hour. See here for details of setting that up
Or if you are using Sql Express see this question "How to run a stored procedure every day in SQL Server Express Edition?"
Ideally you wouldn't do this using IIS etc, unless there is some reason you don't have access to the database.

You can use Timer.
If you use SQL Server you can also schedule a job on the DB directly.

I would agree with brodie. Alternativly create a SSIS package and run either as a SQL Job or a scheduled task from command line(using DTEXEC).
http://msdn.microsoft.com/en-us/library/ms365302.aspx - Shows you how to create a basic solution.
http://decipherinfosys.wordpress.com/2008/09/17/scheduling-ssis-packages-with-sql-server-agent/ - Shows you how to schedule your task.
For your exercise either would do the trick. I would suggest using either that you feel more familiar with. But certainly wouldnt suggest creating a timer driven service.

You could create a webpage that accomplishes this and use a free service like pingdom.com to call that page every hour.
EDIT:
Mine is the easy route, probably not the best solution but quick and simple
You can check this out also:
https://blog.stackoverflow.com/2008/07/easy-background-tasks-in-aspnet/

see this example for creating a new thread in global asax, http://www.mikesdotnetting.com/Article/129/Simple-task-Scheduling-using-Global.asax
Be aware though if the website goes down the process will not continue to run, if this is a problem a sql batch job or windows service would be better suited, and if the task is resource intensive it would be better to do this on another machine anyway as the global asax method will take away processing resources from your website

Database Scheduled manipulation

I've wrote a Restaurant Management application.
I have a Database based on SQL Server 2005 which has one table named OrdersItems. Every 5 minutes I want to read all rows of this table and based on a specific criteria Update some fields.
I don't want to do that in my main application and I prefer to have an Alternative engine to perform this.
Which method is the best method to perform such task ? Also note that this Table (OrdersItems) is under process every time because main application must be always running and get new Restaurant Orders.

You can create a SQL Server Agent job that does the update every five minutes.
If you are using SQL Server Express edition, you can't use SQL Server Agent because it's only included in the "bigger" versions of SQL Server.
In this case, you can create your jobs manually using batch files and Windows Task Scheduler.

I definitely agree with Christian and dougajmcdonald's points about using SQL Task/ Maintenance. However since you included c# in your tags an alternative is to create a Windows Service.
The benefits of this approach
Can run on a machine that doesn't have the SQL Server Agent installed (including express editions)
Can be run outside the context of a user login.
Has standard stop start pause continue mechanism that's well understood.
If the service itself fails will likely result in an event log
This answer contains a template for a windows service that periodically gets data and executes. You may simply want to change the DoStuff method to execute a stored procedure

Create a dialog timer and let it activate a stored procedure. This has the advantage of being fully contained inside the database (no external process), it does not require SQL Agent (runs on Express) and is completely crash resilient at the point it will survive database detach/attach and backup/restore operations (the scheduled job will run after recovery on the new restored database).

I would expect a SQL Task / Maintenance plan would be the best for this.
You can set them up for whatever interval you want, specifying a SQL statement, maintenance task etc you want to run.
You can also setup alerts etc if you want to know when it fails for example.

Deploy a cron job on a server with access to the database which is started every 5 minutes and processes your data, using transactions. I see one problem there: If the amount of data to be processed is large, it could quite work more than five minutes.

Exec Console Application by using TSQL SP?

I have a console application (in C#) to read data from SQL server (Microsoft SQL 2005) and write data to SQL server. What I need right now is to add a trigger to a table to exec the console application when any row of data is changed.
Not sure what SP available on Microsoft SQL server (2005) to launch a console application? and how can I pass the result from app back? Will it be run as sync or asych manor? Is there any permission issue I have to configure?

Don't launch external processes from a trigger, you'll bring the server onto its knees. Doesn't matter if is xp_cmdshell or CLR procedure. Instead use Service Broker and issue a SEND in your trigger to queue a message to a local service and rely on activation to do the external dependent processing, asynchronously and on a separate context.

The xp_cmdshell stored procedure can be used to launch an external process but this is often disabled for security reasons.
As the console application is already written in C#, perhaps it could be re-written as an SQLCLR stored procedure?

This seems a little shaky to me. Is there any chance of the trigger being called frequently, leading to many launches of the application? Also, I don't think the trigger will complete until the console application has finished or failed. Meantime, the operation that caused the trigger to fire will still be waiting.
Does the application need to run right away? If not, then maybe you could run this as a SQL Agent job periodically.

Trigger slow things down and in your case, this will lead to mass chaos. Triggers is not the route you want to take here.
You might want to consider having a console app that polls the database and every time it finds changes, it will display the changed rows for the users consumption.
You can track these changes using a field like [LastUpdatedDateTime] with a default of GetDate(), and don't send this value in your query. Therefore it will always have the latest timestamp of change. You can alternatively, have an audit table that gets filled by a trigger.

I agree with Ken, you might want to think about changing the architecture. Is the console application reading and writing data to the same SQL server that is invoking it? If so you are better off coding that logic into the trigger or stored procedure itself, and/or changing your database schema to make it so your logic doesn't have to be so complicated.