Sqlite

#JSON操作：

insert into tag (data) values ('{"id":2, "character":[{"id": 2, "name":"demo","task":[{"id":3,complete:false}]}]}');
select json_extract(b.value, '$.id')
 from
  tag,
  json_each(json_extract(data,'$.character')) a, 
  json_each(json_extract(a.value,'$.task')) b 
   where 
    json_extract(b.value,'$.complete')=0