This is the built-in help made by Microsoft for the command 'Undo-Transaction', in PowerShell version 2 - as retrieved from
Windows version 'Microsoft® Windows Vista™ Ultimate ' PowerShell help files on 2016-06-23.
For PowerShell version 3 and up, where you have Update-Help, this command was run just before creating the web pages from the help files.
Rolls back the active transaction.
Undo-Transaction [-Confirm] [-WhatIf] [<CommonParameters>]
The Undo-Transaction cmdlet rolls back the active transaction. When you roll back a transaction, the changes made by the commands in the transact
ion are discarded and the data is restored to its original form.
If the transaction includes multiple subscribers, an Undo-Transaction command rolls back the entire transaction for all subscribers.
By default, transactions are rolled back automatically if any command in the transaction generates an error. However, transactions can be started
with a different rollback preference and you can use this cmdlet to roll back the active transaction at any time.
The Undo-Transaction cmdlet is one of a set of cmdlets that support the transactions feature in Windows PowerShell. For more information, see abo
ut_Transactions.
<
Online version: http://go.microsoft.com/fwlink/?LinkID=135268
about_Transactions
about_Providers
Start-Transaction
Get-Transaction
Complete-Transaction
Use-Transaction
<
-------------------------- EXAMPLE 1 --------------------------
C:\PS>undo-transaction
Description
-----------
This command rolls back the current (active) transaction.
-------------------------- EXAMPLE 2 --------------------------
C:\PS>cd hkcu:\software
PS HKCU:\Software> start-transaction
PS HKCU:\Software> new-item MyCompany -usetransaction
PS HKCU:\Software> undo-transaction
Description
-----------
This command starts a transaction and then rolls it back. As a result, no changes are made to the registry.
-------------------------- EXAMPLE 3 --------------------------
C:\PS>cd hkcu:\software
PS HKCU:\Software> start-transaction
PS HKCU:\Software> new-item MyCompany -usetransaction
PS HKCU:\Software> get-transaction
RollbackPreference SubscriberCount Status
------------------ --------------- -----
Error 1 Active
PS HKCU:\Software> start-transaction
PS HKCU:\Software> get-transaction
RollbackPreference SubscriberCount Status
------------------ --------------- -----
Error 2 Active
PS HKCU:\Software> undo-transaction
PS HKCU:\Software> get-transaction
RollbackPreference SubscriberCount Status
------------------ --------------- -----
Error 0 RolledBack
Description
-----------
This example demonstrates that when any subscriber rolls back a transaction, the entire transaction is rolled back for all subscribers.
The first command changes the location to the HKCU:\Software registry key.
The second command starts a transaction.
The third command uses the New-Item cmdlet to create a new registry key. The command uses the UseTransaction parameter to include the change in t
he transaction.
The fourth command uses the Get-Transaction cmdlet to get the active transaction. Notice that the status is Active and the subscriber count is 1.
The fifth command uses the Start-Transaction command again. Typically,
starting a transaction while another transaction is in progress occurs when a script used by the main transaction includes its own complete trans
action. (This example is done interactively so that you can examine it in stages.)
When you enter a Start-Transaction command while another transaction is in progress, the commands join the existing transaction as a new "subscri
ber" and the subscriber count is incremented.
The sixth command uses the Get-Transaction cmdlet to get the active transaction. Notice that the subscriber count is now 2.
The seventh command uses the Undo-Transaction cmdlet to roll back the transaction. This command does not return any objects.
The final command is a Get-Transaction command that gets the active (or in this case, the most recently active) transaction. The results show tha
t the transaction is rolled back, and that the subscriber count is 0, showing that the transaction was rolled back for all subscribers.