Deleting the list items at a time from list using batch command in SharePoint 2007

When we are working with SharePoint, especially when programming we can discover plenty of things. Because SharePoint is a very big system and it is pretty much good for the developers and administrators that they can discover more and explore more. Its a lovely product and I really love it from Microsoft. From my experience in SharePoint i thought of placing all the SharePoint stuff in my blog. So now we are going to discuss about the performance and operations we need to perform in coding when dealing with SharePoint objects.
When we do SharePoint coding we need to think a minute about the efficiency and performance of the code . For example, if you take a person object, it has some properties around 10-15 and if you don’t dispose it from memory then we don’t get serious problems. But where as we dealing with SharePoint objects like SPSite and SPWeb etc, these are very big and occupies lot of memory than objects what we use every day in C#. So, don’t forget to use Using keyword for them so that they will be disposed and removed from memory when it’s scope is over automatically.
Another performance related is performing common operation to all list items in a list in SharePoint. Usually we will write a foreach statement to loop through all the list items in a list and perform operation. i.e. add, edit or delete. When we need to update all the list items and columns, data varies dynamically then  we need to write a update command inside the foreach statement. But when we know that we are updating the same columns with same data for all items then we shouldn’t follow the code by writing update statement in foreach statement. Because it will be very costly and time taking. It will use lot of resources multiple times. So for this, Microsoft SharePoint team already integrated beautiful feature in SharePoint system. i.e. called Batch programming for doing operations on list items. This is the most efficient way of deleting or updating in a single list.
Below is the code i use to delete all the list items in a SharePoint list.

private void DeleteAllItemsUsingBatch()
    {
        using (SPSite site = new SPSite("http://mySharePointServer"))
        {
            SPWeb web = site.OpenWeb("/");
            SPList list = web.Lists["Links"];
            StringBuilder sb = new StringBuilder();
            sb.Append("");
            string batchCommand = "<method><setlist scope=\"Request\">" + list.ID + "</setlist><setvar name=\"ID\">{0}</setvar><setvar name=\"Cmd\">DELETE</setvar></method>";
            foreach (SPListItem item in list.Items)
            {
                sb.Append(string.Format(batchCommand, item.ID.ToString()));
            }
            sb.Append("");
            web.AllowUnsafeUpdates = true;
            site.RootWeb.ProcessBatchData(sb.ToString());
            web.AllowUnsafeUpdates = false;
            web.Close();
        }
    }

Below is the code for deleting all library items in a document library. Remember, the only difference is for document libraries we have files as the primary fields. So, we should specify the file name along with the other parameters. So, find below code.

private static void DeleteAllItemsUsingBatch()
        {
            using (SPSite site = new SPSite("http://mysharepointserver"))
            {
                SPWeb web = site.OpenWeb("/");
                SPList list = web.Lists["Documents"];
                StringBuilder sb = new StringBuilder();
                sb.Append("");
                string batchCommand = "<method><setlist scope=\"Request\">" + list.ID + "</setlist><setvar name=\"ID\">{0}</setvar><setvar name=\"Cmd\">DELETE</setvar><setvar name=\"owsfileref\">{1}</setvar></method>";
                foreach (SPListItem item in list.Items)
                {
                    sb.AppendFormat(batchCommand, item.ID.ToString(), item.File.ServerRelativeUrl);
                }
                sb.Append("");

                web.AllowUnsafeUpdates = true;
                site.RootWeb.ProcessBatchData(sb.ToString());
                web.AllowUnsafeUpdates = false;
                web.Close();
            }
        }

Explore more and know more. Happy Coding!!!