How do I query items that are sourced in another site collection?

Question

I have a set of site collections (call it 'Personals'). Each of these site collections has a page on the root site that wants to display a feed of 'announcements'. These 'announcements' need to be declared in a centralized location (like in a list on some central site collection). How do I create an 'announcements' feed on each site in 'Personals' that uses as its source the 'announcements' declared in the central location?

This is my best guess on what to do: Make an 'announcement' content type; create a central site collection; create a list that uses the 'announcement' content type on the central site collection and fill it with my announcement items; for each site in 'Personals', setup some sort of content query web part that queries against all items from the central site collection with the content type 'announcement' (or create a custom web part that does this query in code-behind).

What I'm unsure about in the above process is: Is this even remotely the right approach? Where do I declare the 'announcement' content type? On each site collection? Or can I put it in some larger scope? Is there a way to configure out-of-the-box web parts (maybe the Content Query web part?) to query items sourced in a central location? Or do I need to write a custom web part to do this?

Edit: Assume in this scenario that our 'announcements' have extra columns not provided by the OOTB announcements list type. (In actuality, I need to find a way to query items with many different data types, not just announcements, some of these data types don't fit into any of the OOTB content types or list types.)

Answer 1

There are several ways to do it:

1. Fastest - use Search - e.g. using "contentclass" (see here http://spreflections.wordpress.com/2010/04/18/leverage-search-crawl-rules-and-content-class-property-to-refine-sharepoint-search-result/) you can simply target across WHOLE farm actually. Then is a matter of creating your Content type, managed properties and update CoreSearchREsults web part to search your own information - using even a Search Scope for it.
2. Using Listdata.svc - in a HTTP handler to cross Site collections - others use it to enable Cross-site collection navigation
3. Using BDC as evoqued here above - this also means your data is same retrieved via a WEb Service call (typically ListData.svc or Lists.asmx).

All other are way more involving demanding CODE.

Hope it helps, C:\Marius

Answer 2

There is an OOTB Announcements list, I'm assuming this is what you need to be using. Then it's just like any other list. You might be able to do what you need with the List Viewer web part, but the total requirements are unclear. I did something similar with a scrolling news ticker based on an OOTB Announcements list and Silverlight (though a custom web part would work as well).

When you say "Personals" do you mean My Sites? Because if so you will need to be careful about accessing data across web applications (you may run into additional "issues" depending on how you tackle this, and based on the production set up).

Other than that, it looks like you're heading in the right direction. Just remember "Announcements" is an OOTB list so you don't need to make a custom content type. It's just a plain old SPList.

Answer 3

SharePoint external lists? and then you Show your external list like a webpart in your site collection.

Another Complete sample http://www.spmcm.me/Blog/Lists/Posts/Post.aspx?List=3e60f91e%2D5dbe%2D4719%2D9ef5%2D5cf704858113&ID=41&Web=59b5f6cb%2Dd9cd%2D4dc9%2Daba7%2Dc142b69d2036

BCS my friend, regards.