WordPress database error Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8mb4_unicode_520_ci,COERCIBLE) for operation '=' for query SELECT p.ID, pm.meta_value, p.post_type, p.post_status FROM mdea_posts AS p INNER JOIN mdea_postmeta AS pm ON (pm.post_id = p.ID) WHERE pm.meta_key = 'custom_permalink' AND (pm.meta_value = 'tag/n-二甲基乙氨基乙二醇' OR pm.meta_value = 'tag/n-二甲基乙氨基乙二醇/') AND p.post_status != 'trash' AND p.post_type != 'nav_menu_item' ORDER BY FIELD(post_status,'publish','private','pending','draft','auto-draft','inherit'), FIELD(post_type,'post','page') LIMIT 1 made by require('wp-blog-header.php'), wp, WP->main, WP->parse_request, apply_filters('request'), WP_Hook->apply_filters, Custom_Permalinks_Frontend->parse_request WordPress database error Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8mb4_unicode_520_ci,COERCIBLE) for operation '=' for query SELECT p.ID, pm.meta_value, p.post_type, p.post_status FROM mdea_posts AS p INNER JOIN mdea_postmeta AS pm ON (pm.post_id = p.ID) WHERE pm.meta_key = 'custom_permalink' AND (pm.meta_value = 'tag/n-二甲基乙氨基乙二醇' OR pm.meta_value = 'tag/n-二甲基乙氨基乙二醇/') AND p.post_status != 'trash' AND p.post_type != 'nav_menu_item' ORDER BY FIELD(post_status,'publish','private','draft','auto-draft','inherit'), FIELD(post_type,'post','page') LIMIT 1 made by require('wp-blog-header.php'), require_once('wp-includes/template-loader.php'), do_action('template_redirect'), WP_Hook->do_action, WP_Hook->apply_filters, Custom_Permalinks_Frontend->make_redirect