Custom admin page: How to save changes specific to users

Then save the data in the usermeta table, linked to each user, by update_user_meta() and get_user_meta() functions. get_current_user_id() gives you the $user_id to pass. Choose a $meta_key that wion’t create conflict, preferrably with a unique prefix. Same rule as for keys for saving data in options table.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)