Below is the CAML Query to get All the task assigned to me or the group I am part of. And only tasks which are not complete.
<Query>
<GroupBy Collapse=”TRUE” GroupLimit=”50″>
<FieldRef Name=”AssignedTo”/>
</GroupBy>
<OrderBy>
<FieldRef Name=”Created” Ascending=”FALSE”/>
</OrderBy>
<Where>
<And>
<Or>
<Membership Type=”CurrentUserGroups”>
<FieldRef Name=”AssignedTo”/>
</Membership>
<Eq>
<FieldRef Name=”AssignedTo”/>
<Value Type=”Integer”>
<UserID/>
</Value>
</Eq>
</Or>
<Neq>
<FieldRef Name=”Status”/>
<Value Type=”Text”>Completed</Value>
</Neq>
</And>
</Where>
</Query>
<ViewFields>
<FieldRef Name=”Created”/>
<FieldRef Name=”LinkTitleNoMenu”/>
<FieldRef Name=”Status”/>
<FieldRef Name=”Title”/>
<FieldRef Name=”ID”/>
<FieldRef Name=”WorkflowLink”/>
</ViewFields>
</Query>
Some cool SPQuery Links
http://mosswat.blogspot.com/2009/03/spquery-syntax.html
http://www.codebanking.com/articles/sharepoint/construct-sharepoint-caml-query.asp
How to Set Null Values to Query
Working with Large Lists in SharePoint 2010 – List Throttling