My SQL function to change user_name

This should be working:

Be sure that your DB prefix is “wp_”

Update wp_users set wp_users.user_login=wp_users.user_nicename where wp_users.user_login="x" 

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