Меняем кодировку у всех таблиц в базе данных MySQL разом.

SELECT CONCAT('ALTER TABLE `', t.`TABLE_SCHEMA`, '`.`', t.`TABLE_NAME`, '` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;') as sqlcode
FROM `information_schema`.`TABLES` t
WHERE 1
AND t.`TABLE_SCHEMA` = 'db_name'
ORDER BY 1

ALTER TABLE `zabbix`.`acknowledges` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`actions` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`alerts` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`applications` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`auditlog_details` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`auditlog` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`autoreg_host` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`conditions` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`config` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`dchecks` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`dhosts` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`drules` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`dservices` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`escalations` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`events` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`expressions` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`functions` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`globalmacro` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`graphs_items` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`graphs` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`graph_theme` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`groups` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`help_items` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`history_log` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`history_str_sync` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`history_str` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`history_sync` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`history_text` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`history_uint_sync` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`history_uint` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`history` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`hostmacro` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`hosts_groups` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`hosts_profiles_ext` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`hosts_profiles` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`hosts_templates` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`hosts` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`housekeeper` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`httpstepitem` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`httpstep` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`httptestitem` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`httptest` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`ids` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`images` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`items_applications` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`items` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`maintenances_groups` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`maintenances_hosts` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`maintenances_windows` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`maintenances` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`mappings` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`media_type` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`media` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`nodes` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`node_cksum` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`opconditions` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`operations` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`opmediatypes` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`profiles` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`proxy_autoreg_host` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`proxy_dhistory` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`proxy_history` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`regexps` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`rights` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`screens_items` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`screens` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`scripts` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`services_links` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`services_times` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`services` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`service_alarms` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`sessions` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`slideshows` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`slides` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`sysmaps_elements` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`sysmaps_links` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`sysmaps_link_triggers` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`sysmaps` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`timeperiods` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`trends_uint` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`trends` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`triggers` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`trigger_depends` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`users_groups` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`users` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`user_history` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`usrgrp` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;
ALTER TABLE `zabbix`.`valuemaps` CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;