A timer for a service read a table in the comic book

Question

I need to get a service to read a table in the comic book every 5 or 10 seconds. I don’t see any other way to do that. When in this table a certain Flag is changed, then the service pushes a message to an App. I don’t know if this is the best way to automate my App, but it’s what’s coming into my head right now and I have no idea how to do it. The lambda that checks the table ok, I do not know if the timer or something else, how to do. How do I implement this timer? The idea would be to create a Task(async) that reads the table, but the problem is the timer. Web Api usage with REST and C#.

Answer 1

Using a timer in a web API is not a good idea. I would create another project, like windows service, and then use a timer.

Another option, and it depends on your database, would be to create a Rigger that makes the call from your web api in the act of the change you expect. For SQL Server a look here. In short:

Declare @Object as Int;
Declare @ResponseText as Varchar(8000);

Code Snippet
Exec sp_OACreate 'MSXML2.XMLHTTP', @Object OUT;
Exec sp_OAMethod @Object, 'open', NULL, 'get',
                 'http://www.webservicex.com/stockquote.asmx/GetQuote?symbol=MSFT', --Your Web Service Url (invoked)
                 'false'
Exec sp_OAMethod @Object, 'send'
Exec sp_OAMethod @Object, 'responseText', @ResponseText OUTPUT

Select @ResponseText

Exec sp_OADestroy @Object

Now, honestly, I would never, ever, under any circumstances, use a while(true). In addition to being inelegant, and having other alternatives, the web api waits for a first request to be started. Thus, it is yours while(true) will only start working after this request, the same applies to the timer.