I've got a state machine workflow implemented using WorkflowFoundation 4.1. I'm using the SQL Server persistence store and the WorkflowApplication class for loading and running workflows.
I'm making changes to the state machine workflow model, and am finding that existing instances break very easily. I've written code that can replay the workflow back into the correct state, which is basically a migration, which works fine, however I need to be able to clear out the old workflow instance as well.
The main issue is that if the workflow is invalid, I can't even load it, so I can't terminate or cancel it either.
Is there a way to use the workflow API to remove a workflow without loading it (ie, some command on the SqlPersistenceStore), or do I have to clean the database manually?
The SqlWorkflowInstanceStore doesn't allow you to do so directly. You will need to go into the database and delete the record there. If you are using AppFabric there is actually a command to delete a workflow instance without loading it first for just that purpose. There should be a PowerShell command to do that using code.