Best Object Model Coding Practices for SharePoint 2007

I was working on performance tuning a SharePoint 2007 application and these are the common bad coding practices which developers make unintentionally.
Never Use SPList.Items.GetItemById(ID):
Refer this link for further details
http://www.3guysonsharepoint.com/?p=197
SPWeb.EnsureUser Vs. SpWeb.AllUsers:
The best way to check if the user exists / have access to the site / web is this way.
SPWeb.AllowUnsafeUpdates = true;
SPUser user = webInUserContext.EnsureUser("ad\\C001234");
SPWeb.AllowUnsafeUpdates = false;
Don't forget to use AllowUnsafeUpdates if the logged in user only has read/contribute permissions, otherwise you will get "Access Denied". It is not necessary to use AllowUnsafeUpdates if you are running code with elevated privileges or impersonation.
http://blog.qumsieh.ca/2008/06/26/spweb-siteusers-vs-spweb-users/
This is not a good way.
SPUser user = webInUserContext.AllUsers["ad\\C001234"];
Windows SharePoint Services 3.0 SDK
SPWeb.AllUsers – Gets the collection of user objects that represents all users who are either members of the site or who have browsed to the site as authenticated members of a domain group in the site.
SPWeb.SiteUsers – Gets the collection of all users that belong to the site collection.
SPWeb.Users – Gets the collection of user objects that are explicitly assigned permissions on the Web site.
SPWeb.EnsureUser - Checks whether the specified login name belongs to a valid user of the website, and if the login name does not already exist, adds it to the website.
Best way of Accessing SharePoint Groups:
I think this is the best way of accessing SharePoint groups if we know the name of the group.
SPGroupCollection groupColl = newWeb.SiteGroups.GetCollection(new String[] { "Readers", "Contributers" });
This one gets SharePoint groups only which you want where as below one gets all the SharePoint Groups
SPGroupCollection groupColl = newWeb.SiteGroups;
Efficient way of adding list item to SharePoint list:
Refer the link below
http://msdn.microsoft.com/en-us/library/bb687949(office.12).aspx
public static class Extensions
{ /*efficient way of adding list item to SharePoint list
* http://msdn.microsoft.com/en-us/library/bb687949(office.12).aspx */
public static SPListItem AddItem(this SPList list)
{
const string EmptyQuery = "0";
SPQuery q = new SPQuery { Query = EmptyQuery };
return list.GetItems(q).Add();
}
}
Usage…
SPListItem item = list.AddItem();
List item query elapsed time:
I got this message in the SharePoint ULS log.
01/21/2011 10:30:02.00 w3wp.exe (0x1320) 0x1944 Windows SharePoint Services Database 8sli Monitorable List item query elapsed time: 4508 milliseconds, Additional data (if available): Query HRESULT: 0 List internal name, flags, and URL: {A134D627-5580-49FD-883C-9D1325CE6CD3}, flags=0x0000000020801088, URL="http://SiteURL/Lists/Tickets/AllItems.aspx" Query XML: "<Query><OrderBy><FieldRef Name="Modified" Ascending="FALSE"/></OrderBy></Query>" SQL Query: " SELECT TOP 101 t1.[Type] AS …….
I was wondering what this message in the SharePoint ULS log means, finally figured out that this message is logged whenever we try to load a SharePoint List View which has large number of rows and which does not use default view sorting order (List Item ID)
I our case our SharePoint List had 1,000,00 rows in it and the AllItems View is being sorted by Last modified descending.
Select Distinct or Unique values from SharePoint List column:
Refer the link below
http://blog.visualstudioteamsystem.com/post.aspx?item=33
if (web.ServerRelativeUrl == "/")
{
ticketsList = (SPList)web.GetList(ticketsListURL);
}
else
{

ticketsList = (SPList)web.GetList(string.Concat(web.ServerRelativeUrl, ticketsListURL));
}
SPField field = ticketsList.Fields.GetFieldByInternalName("CreatedByHistorical");
object[,] values;
uint numberValues = ticketsList.GetDistinctFieldValues(field, out values);
for (int i = 0; i < numberValues; i++)
dropDownListEnterers.Items.Add(values.GetValue(0, i).ToString());