Here’s a quick follow-up to my previous post on dealing with SharePoint list view thresholds. I just bumped up against another case where I had to change some code to deal with it.

To recap the project a bit, I am writing a console app that will import a bunch of data into a SharePoint site. Since I’m human, and I make mistakes, the first step of this importer is to delete any existing data in those lists (which would be leftover from the previous test run).

I had a simple solution for doing that, deleting records in batches of 100, based somewhat on this example. I assumed that would work OK, even with larger lists, but I didn’t take into account that the first step in my process was to get all items in the list. That, of course, fails for a very large list. So I had to change my code to initially get only the first 4000 records in the list. (That can be done with the RowLimit clause in CAML.) Then, I delete from that subset in batches of 100. Then, I just repeat that until there are no more records left.

As far as I can tell, there’s no SharePoint CSOM equivalent to SQL’s “truncate table”, which would have made this much easier. And I feel like I’m probably still not doing this in the most efficient way. If I was creating a process that needed to do this repeatedly, instead of just a few times, I’d dig into it some more. And if I was retrieving items instead of deleting them, I’d probably do something with ListItemCollectionPosition.