select a.id as _id, a.name as _name, a.role_id as _role_id, b.role_name as _role_name,
a.c_time as _c_time, c.labels as _labels from user a
left join role b on b.id=a.role_id
left join (select user_id, group_concat(label order by id desc separator ';') as labels from label
group by user_id) c on c.user_id=a.id

比如针对user 表 id=2 的 主表数据清理子表 label，单条单条清理，数据能同步，但是清理 完label 里面 user_id=2的数据，es 数据不能清空。。这是bug？