the link between the event and the workflow it created is not stored directly in the DB unless you turn the event trace (transaction SWEL) on, and then it is stored in the event trace tables, however it is not recommended to have the trace active in a production system since there a lot of events and the trace tables will get very large very fast.
Usually if I want to see the workflow created I look at the object in table sww_wi2obj / use the sap_wapi_workitems_to_object.