mysql> set names utf8mb4 collate utf8mb4_unicode_520_ci; mysql> select 'a' = 'a '; +--------------+ | 'a' = 'a ' | +--------------+ | 1 | +--------------+ mysql> set names utf8mb4 collate utf8mb4_0900_ai_ci; mysql> select 'a' = 'a '; +--------------+ | 'a' = 'a ' | +--------------+ | 0 | +--------------+ 9