If you initially set up some users locally on the wiki and then add the LDAP authentication service, you may notice that when the same users (with the same usernames) login via LDAP, new accounts are created with a 1 appended after the name. For example, you create a local account Bob and then login using LDAP authentication also as username Bob, a new account will be created with the username Bob1.
To
convert your existing users to be able to login with the external
authentication provider instead you'll need to perform some updates to
your users table. Specifically you'll need to set the user_service_id
to the id of the authentication service, and set your
user_external_name to the current username.
update users
set user_service_id = 8,
user_external_name = user_name
where user_name in ("Bob", "Susan");
In this case we're changing the local accounts Bob and Susan to login via the external authentication service at id 8. You can find the id of your authentication service from the services table.