applaction.yml

    dataSource:
        url: jdbc:mysql://127.0.0.1:3306/databases?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull

my.cnf
    [client]
    default-character-set = utf8mb4
    [mysql]
    default-character-set = utf8mb4
    [mysqld]
    character-set-client-handshake = FALSE
    character-set-server = utf8mb4
    collation-server = utf8mb4_unicode_ci