Recursive Vs. Recursiveall: Understanding Caml Query Scope For Sharepoint Libraries

The Problem: Recursive vs RecursiveAll

When querying items in SharePoint libraries using CAML (Collaborative Application Markup Language), a common challenge is understanding the difference between a recursive and recursiveAll query. Both retrieve items from folders within the library, but have different scope and performance implications.

A recursive query retrieves items only from the current folder and any sub folders beneath it. A recursiveAll query retrieves all items in the current folder, sub folders, and also any other items in the library not inside folders.

Choosing the wrong one can lead to unexpected query results. Understanding when to use each approach is key to efficiently accessing folder hierarchies in document libraries and list items in SharePoint.

How Scope Works in CAML Queries

CAML query scope controls which items are returned based on the location within the SharePoint library structure. There are three basic types of query scope:

• Folders Only – Retrieves items only from the target folder and sub folders.
• All Items – Retrieves all items in the library regardless of folder structure.
• Recursive – Retrieves the target folder, sub folders, but skips any items not in folders.

Query scope is set within the CAML element using attributes like Folder, Recursive, and RecursiveAll. Understanding the interactions between folder hierarchy and query scope is key.

Folder Hierarchy Implications

SharePoint libraries can have deep folder structures with many levels of sub folders. Where a query is executed within that hierarchy impacts which items it has access to.

For example, a query run from the root folder has access to all items. But the same query run from a sub folder will only access items within its local hierarchy branch.

Query Scope Access

Query scope then controls which of the available items are returned from the folders accessible to where the query was executed:

• Folders Only – Just return items from accessible folders.
• All Items – Return everything the folder hierarchy grants access to.
• Recursive – Return a subset excluding any list items not in folders.

Understanding this interplay is key to crafting queries that target the correct item set. Choosing recursive vs recursiveAll depends largely on the folder context a query is executed from.

When to Use Recursive vs RecursiveAll

The key difference between recursive and recursiveAll centers around including or excluding items not inside folders from the query results.

Generally recursive is used to query documents while recursiveAll is used for list items. But folder context also plays a role.

Retrieving Files in Folders

When working with document libraries, items tend to be stored inside folders. In this case, recursive queries are most appropriate as they will retrieve documents from the current folder down through all sub folders.

Using recursive avoids also pulling back documents uploaded to the root library container outside any folders. This better matches the expected scope of “retrieve all documents in my folder structure” in many scenarios.

Accessing List Items in Folders

Custom SharePoint lists can leverage folders for organization but also often have items added directly to the root container. In this case recursiveAll is generally the better approach.

It will retrieve the current folder’s items, traverse any sub folders, but also return other list items not stored inside folders. This gives the full set of available list items based on the current security context.

Code Examples

Some key points seen the differences between recursive and recursiveAll CAML queries in practice:

Recursive Query on Document Library

When executed from a sub folder, this query will return documents inside it and other sub folders, but skip any documents added directly to the library:

<View Scope='Recursive'>
  <Query>
    <Where>
       <Eq>
          <FieldRef Name='FSObjType' />
          <Value Type='Integer'>0</Value>
       </Eq>
    </Where>
  </Query> 
</View>

RecursiveAll Query on Custom List

In contrast, this recursiveAll query run from a folder in a custom list will also return list items outside folders:

<View Scope='RecursiveAll'>
  <Query>  
    <Where>
       <Neq>   
          <FieldRef Name='FSObjType' />  
          <Value Type='Integer>1</Value>
       </Neq>
    </Where>
  </Query>  
</View>

Key Takeaways

Understanding query scope recursive vs recursiveAll behavior is key for targeting the correct item set in SharePoint libraries. Keep these guidelines in mind:

• Recursive scope will not return list items added directly to a library outside folders.
• RecursiveAll expands the query to also return items outside folders from the current context.
• Folder structure and query execution point impacts which items a scope has access to.
• Generally recursive for documents, recursiveAll for custom lists with folders.

With a handle on folder hierarchies and CAML query scope access, you can better leverage recursive vs recursiveAll approaches in SharePoint libraries for precise and efficient data retrieval.