The query All users enrolled in a course without a role gives you users having "No roles". You should be able to work out how to make any changes directly within the database from this query.
However depending on your needs it's probably better to use a function call, possibly role_assign(). This will ensure appropriate events are triggered within Moodle as there may be internal code or third party plugin code that needs to respond to the changes.
Hi,
Maybe I didn't understand you question, but if you are looking for a way to filter the view of the participants list so you would only see participants with "No roles" status in the "Roles" column, please note that in Moodle 3.8 there is a new filter called "Roles: No roles":
Of course this filter won't automatically change all your records to the requested role ("Student"), but at least it's half the way.
You can get more technical details about this filter and how it was added, here:
MDL-66178 ("Participants list - Filter users with no roles")
Dear Acqua,
There is a table call role_assignments . anyway i manage my situation .thank you
