Adding a new item to a SharePoint List

Using SPList.Items.Add() is not the best way to add a new item to a list. This is because the moment you access the get method on the Items collection it retrieves all the items into memory.

A quick peek at the Microsoft.SharePoint.dll assembly via reflector confirmed it:

 

You may not notice a difference in performance in the dev environment, but once your list starts to grow it will gradually degrade.

I recently learned this the hard way. This is the best way to add a new Item:

SPList list = _Web.Lists[LIST];                    SPQuery query = new SPQuery();
query.RowLimit = 0;
SPListItem item = list.GetItems(query).Add();
item[TITLE] = “testing”;
item.Update();

On an unrelated note, executing a query with a RowLimit generates an underlying SQL query such as  SELECT TOP X ..... where X is the RowLimit value.

I wonder if the behavior is still the same in SharePoint 2010. Hmmm...

References:

• http://blog.robgarrett.com/2009/02/25/efficient-way-to-add-a-new-item-to-a-sharepoint-list/
• http://www.infoq.com/articles/SharePoint-Andreas-Grabner

More best practices on SharePoint:

• http://www.hezser.de/blog/archive/2009/04/08/summary-common-coding-issues.aspx