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Commands : Documents : How to delete or update documents using index?

Sometimes we need to update or delete a large amount of documents answering certain criteria. With SQL this is a simple operation, and a query doing that will look like this:

DELETE FROM Users WHERE LastLogin < '2009-01-01'
UPDATE Users SET IsActive = 0 WHERE LastLogin < '2010-01-01'

This is usually not the case for NoSQL databases, where batch operations are not supported. RavenDB does support them, and by passing it a query and an operation definition, it will run the query and perform that operation on its results.

The same queries and indexes that are used for data retrieval are used for the batch operations, therefore the syntax defining which documents to work on is exactly the same as you'd specified for those documents to be pulled from store.

DeleteByIndex

To issue a batch-delete command you need to specify an index and a query to be sent to it. To minimize the chances of stale results coming back, bulk operations should only be performed on static indexes.

Syntax

Operation DeleteByIndex(
	string indexName,
	IndexQuery queryToDelete,
	BulkOperationOptions options = null);

Parameters
indexName string name of an index to perform a query on
queryToDelete IndexQuery query that will be performed
options BulkOperationOptions various operation options e.g. AllowStale or MaxOpsPerSec
Return Value
Operation Object that allows waiting for operation to complete.

Remarks

Note

DeleteByIndex can only be performed on map index. Executing it on map-reduce index will lead to an exception.

Example

// remove all documents from 'Employees' collection
Operation operation = store
	.DatabaseCommands
	.DeleteByIndex(
		"Raven/DocumentsByEntityName",
		new IndexQuery
		{
			Query = "Tag:Employees"
		},
		new BulkOperationOptions
		{
			AllowStale = false
		});

operation.WaitForCompletion();

UpdateByIndex

Performing a mass-update is exactly the same as making a mass-delete, but this time it uses the Patching API to make it easy for us to define what to do with the documents matching our query.

Syntax

Operation UpdateByIndex(
	string indexName,
	IndexQuery queryToUpdate,
	PatchRequest[] patchRequests,
	BulkOperationOptions options = null);

Parameters
indexName string name of an index to perform a query on
queryToUpdate IndexQuery query that will be performed
patchRequests PatchRequest[] array of patches that will be executed on a query results
options BulkOperationOptions various operation options e.g. AllowStale or MaxOpsPerSec
Return Value
Operation Object that allows waiting for operation to complete.

Example

// Set property 'FirstName' for all documents in collection 'Employees' to 'Patched Name'
Operation operation = store
	.DatabaseCommands
	.UpdateByIndex(
		"Raven/DocumentsByEntityName",
		new IndexQuery
		{
			Query = "Tag:Employees"
		},
		new[]
		{
			new PatchRequest
			{
				Type = PatchCommandType.Set, 
				Name = "FirstName", 
				Value = "Patched Name"
			}
		},
		new BulkOperationOptions
		{
			AllowStale = false
		});

operation.WaitForCompletion();

UpdateByIndex - using JavaScript

Mass-update can also be executed with JavaScript patch.

Syntax

Operation UpdateByIndex(
	string indexName,
	IndexQuery queryToUpdate,
	ScriptedPatchRequest patch,
	BulkOperationOptions options = null);

Parameters
indexName string name of an index to perform a query on
queryToUpdate IndexQuery query that will be performed
patch ScriptedPatchRequest JavaScript patch that will be executed on query results
options BulkOperationOptions various operation options e.g. AllowStale or MaxOpsPerSec
Return Value
Operation Object that allows waiting for operation to complete.

Example

// Set property 'FirstName' for all documents in collection 'Employees' to 'Patched Name'
Operation operation = store
	.DatabaseCommands
	.UpdateByIndex(
		"Raven/DocumentsByEntityName",
		new IndexQuery
		{
			Query = "Tag:Employees"
		},
		new ScriptedPatchRequest
		{
			Script = @"this.FirstName = 'Patched Name';"
		},
		new BulkOperationOptions
		{
			AllowStale = false
		});

operation.WaitForCompletion();

Remarks

Safe By Default

By default, Set-based operations will not work on indexes that are stale, and the operation will only succeed if the specified index is not stale. This is to make sure you only delete what you intended to delete.

For indexes that are updated all the time, you can set a Cutoff in the IndexQuery object you send, which will make sure the operation is executed and that you know what results to expect.

When you are absolutely certain that you can perform the operation when the index is stale, simply set the allowStale parameter to true.