为预热准备更新时间列的查询办法，解决原表中没有索引的问题

drop table t_resource_info_temp;
-- 约30秒
create table  t_resource_info_temp select id,create_time from t_resource_info;  
--     约8秒
alter  table  t_resource_info_temp  add  index  index_create_time(create_time) ;

-- 联合查询
select * from t_resource_info where id in (select id from t_resource_info_temp where create_time between '2016-09-01' and '2016-09-02')


drop table t_resource_structure_temp;
-- 约30秒
create table  t_resource_structure_temp select structure_id,last_updated_time from t_resource_structure;  
--     约8秒
alter  table  t_resource_structure_temp  add  index  index_last_updated_time(last_updated_time) ;

-- 联合查询
select * from t_resource_structure where structure_id in (select structure_id from t_resource_structure_temp where last_updated_time between '2016-09-01' and '2016-09-02')

-- 开始时间
select date_format(min(last_updated_time),'%Y-%m-%d') as start_day from t_resource_structure;

-- 结束时间
select date_format(date_add(now(), interval 1 day),'%Y-%m-%d')  as stop_day;

python脚本的循环日期

begin = datetime.date(2010, 1, 1)
end = datetime.date.today()
d = begin
delta = datetime.timedelta(days=1)
while d <= end:
    print(d.strftime("%Y-%m-%d"))
    d += delta

 N天前的日期

d = datetime.datetime.now() - datetime.timedelta(days=7)
print(d.strftime("%Y-%m-%d"))