--전체 변경
alter table table_name convert to character set utf8;

my.ini 파일 내용 추가 

[mysqldump]
default-character-set = utf8

[mysql]
default-character-set = utf8

[mysqld]
init_connect="SET collation_connection = utf8_general_ci"
init_connect="SET NAMES utf8"
character-set-server = utf8
collation-server = utf8_general_ci

[client]
default-character-set = utf8