Remove tasks with particular workflow from query

[Kelli Keith]

When writing a query for a filter, is there a way to remove tasks that use a certain workflow? My filter uses over 30 projects, and most workflows are okay but I need to remove one set of issues that use a particular project/task workflow. I can't figure it out! Thanks.

[Jack Brickey]

JQL does not inspect workflows. An option would be to create a new issue type and associate to that specific workflow. In that scenario you can easily excluded why is your type, e.g. ...AND type != MySpecialType. 

[Dawid Joshua _TechTime_]

Another idea would be to explicitly exclude issues that use that particular workflow. 
Let's say you have one project AA where the issue type Task and Epic are using the unwanted workflow and a second project BB where Story is using the unwanted workflow.  You could do the following:

JQL:

(<yourExistingFilter>) AND (project = AA AND issuetype not in (Task, Epic)) AND (project = BB AND issuetype != Story)

But as you can see, this can get messy quite quickly. 

Another solution would be to somehow mark the issues on the creation transition on the workflow. You could either use the label field and in the filter add:

(<yourExistingFilter>) AND label != <labelToExclude> 

Or, if you want to make it more discrete (users might ask what this label is for or even delete it), create a custom field, set it on create-transition, and hide it in the field configuration. This goes already deep into the Jira tricks-rabbit-hole, so 
let me know if that's something you'd like to go for and I explain in more detail.