mysql - SQL Error #1071 - Specified key was too long; max key length is 767 bytes -

create table wp_locations (         `id` int(11) not null auto_increment,         `city` varchar(255) not null,         `name` varchar(255) not null,         constraint `city_name` unique (`city`, `name`)     ) default character set utf8mb4 collate utf8mb4_unicode_ci; 

i got sql error '#1071 - specified key long; max key length 767 bytes'

what doing wrong?

mysql reserves max amount utf8 field 4 bytes 255 + 255 default character set utf8mb4 collate utf8mb4_unicode_ci; on 767 max key length limit

you can reduce single varchar lenght or don't use composite key