mysql: revoke privilege "if exists"?

Question

In a script, I want to make sure, a mysql user has no privileges at all on a specific database. So I do:

revoke all privileges on `testdb`.* from 'testuser'@'%'

But if the user does not have any privileges on this database I get this error:

There is no such grant defined for user 'testuser' on host '%'

What is absolutely correct, but my script throws an error now and stops. I do not want to make my script ignoring all errors from this statement.

So is there something like

revoke all privileges if exist ...

I could not find anything about that in the mysql manual.

Answer 1

The mysql command has an -f option which prevents the script from aborting on errors, so you might want to try this:

mysql -u myuser -f < script.sql

Of course this will also ignore other errors which you might not want to be ignored...

Also this unfortunately does not work in combination with the -e option. However if you run mysql from a bash script anyway this can easily be circumvented by using a heredoc:

mysql -u myuser -f <<EOF
REVOKE ALL PRIVILEGES ...
EOF