This is a bug with workaround, but I don’t know where to report these, so I’m writing here and maybe someone will notice.
The rest api documentation for getting list of process instances mentions this parameter:
businessKeyLike Filter by process instance business key that the parameter is a substring of.
But it doesn’t work that way. The query to the database contains like, but no wildcards are added to the parameter, so it will only find exact match. So instead of sending &businessKeyLike=something, one have to send &businessKeyLike=%25something%25. But this is sent straight to the query as a parameter so it might not work on all databases(I don’t know all the databases Camunda supports, but I guess the wildcards might differ).
I’ve tried this on Oracle and H2 and the problem is in the historic rest api as well.