SharePoint 2010: Lists & Events Improvements

• Improved support for Events
• WebAdding & WebProvisioning
• ListAdding & ListAdded
• ListDeleting & ListDeleted
• Post Synchronous events
• SPEventReceiverDefinition.Synchronization (post processing after the commit of the action and before presentation with the result of the post)
• Cancel events & custom error pages
• MSF 4.0 introduces capability to cancel error and redirect user to custom error page
• Synchronous cancel with error URL
• Supported in SharePoint Browser UI only (no client support)
• WSS 3.0 events ran in context of user who triggered event, certain workflow actions were at system level
• WSF 4.0 adds event impersonation (the originating user & user token on SPEventPropertiesBase
• New Registration Capabilities
• New events registration at Site Collection Level
• SPSite & SPWeb event receiver registration via Features
• List Relationships and Joins
• Yes we now can join lists (not like a sql join)
• Set up a relationship first through a lookup field
• Projected fields
• Extra fields pulled from Parent List into view of child list
• no data is saved, it is just in view (read-only)
• show additional secondary data for presentation from parent
• Referential integrity (cascade operations)
• Select operations from both lists using LINQ (SPLinq)
• Supports LINQ, CAML, SPD 2010 (note: LINQ generates CAML under the covers)
• SPQuery.Join, SPQuery.ProjectedFields
• New Security considerations & issues
• Large List Support
• MSF 4.0 can now support 50 Million items (previously recommended 2000 for optimal performance)
• Configuration options per web application
• Admins can request privileged operations
• Two threshold (configurable using PowerShell)
• Warning threshold (2000 items)
• Throttling threshold (5000 items, error message when 5000 limit is reached)
• override query safety checks
• Normal user – 5000 items
• Super User – 20,000 items
• Configure time window for expensive queries (set time for expensive queries)
• Wide List Throttling
• SPListItem limited to 8K of data
• maximum number of joins – 6 , > 6 error is thrown
• Mark columns unique
• Unique columns must be indexed
• Existing data is validated for uniqueness
• uniqueness determined by SQL-collation (case sensitivity)
• List Item and Field Validation
• New column-level & row-level constraints on Lists & List Items

Query whole site collection using SPSiteDataQuery

Using the SPQuery class you can query one SharePoint list for items.

To set up a query across a whole site collection you can use the SPSiteDataQuery object.

The following method fetches all .doc files from all doclibs of the site collection and prints out a list of urls to those items.

public void TestSiteDataQuery() {   using (SPSite site = new SPSite("http://localhost"))   {     using (SPWeb web = site.OpenWeb("/"))     {       SPSiteDataQuery query = new SPSiteDataQuery();         // Search in doclibs only       query.Lists = "";         // Only .doc files       query.Query =       @"                                     doc                    ";         // Select only needed columns: file reference       query.ViewFields = "";         // Search in all webs of the site collection       query.Webs = "";         // Perform the query       DataTable table = web.GetSiteData(query);         // Generate an absolute url for each document       foreach (DataRow row in table.Rows)       {         string relativeUrl =            row["FileRef"].ToString().Substring(             row["FileRef"].ToString().IndexOf("#") + 1);         string fullUrl = site.MakeFullUrl(relativeUrl);           // Write urls to console         Console.WriteLine(fullUrl);       }     }   } }

SPQuery Few important things

1. Always specify the RowLimit to get limited results.

1. oQuery.RowLimit = 100;

2. To Get the Search Items from the sub folders of the list using SPQuery you can do following. Check here

1. SPQuery.ViewAttributes = "Scope='Recursive'";

2. or

3. SPQuery.ViewAttributes = "Scope='RecursiveAll'";

3. Be sure to create a new SPQuery instance each time you use it. You cannot create one SPQuery instance and then reuse it multiple times in a loop where you alter the SPQuery's Query value.

1. for (int i = 0; i < 10 ; i++)

2.

3. SPQuery oQuery = new SPQuery();

4. oQuery.Query = ""+i +"Value>Eq>Where>";

5. SPListItemCollection collListItems = list.GetItems(oQuery);

4. SPQuery query object doesn't need to include tags

1. oQuery.Query = " name="Status"> type="Text">Completed";

5. If you want to do CAML query which also consider the time in datetime fields then try this

1. oQuery.Query = " Name='Created'/> Type='DateTime' IncludeTimeValue='TRUE'> />Value>

6. SPQuery can't be used to search across site collection.One can use SPSiteDataQuery class to search across multiple Lists.

To query the lookup based value items

1. oQuery.Query = " name="Employee" lookupid="TRUE"> type="User">1";

7. To restrict the items to approved, use moderationtype attribute. more details here

1. SPQuery.ViewAttributes = "Scope='Recursive' ModerationType='HideUnapproved'";

8. If you want your query to return empty columns, you have to add Nullable='TRUE' to the viewfields.

1. query.ViewFields="";

To get the item related within past few days , you can use OffsetDays attribute along with Today.

1. query.Query = "";

Article:
SPQuery Best Practice