在客户实际业务中由于库存盘点比较费时，通常会在月末进行一次统一盘点，而不会每日进行库存盘点。

但是模型探索过程中经常会需要日末库存或周末库存的数据，因此需要根据出入库数据进行汇总计算得到期末库存。

附件df_io.csv是一份出入库数据表，其中各字段含义如下：

SELECT * from df_io where date_io >= '2018/01/01' and date_io <= '2018/12/31'
set @dt = '2018-11-07 20:18:40'
set @dt1 = '2017-10-05'
SELECT WEEK(@dt1)
SELECT NOW()
SELECT * FROM a1
-- 计算得到门店、款号、颜色、尺码、每周的期末库存
select store_id,prod_id,color_id,size,WEEK(date_io),sum(quant_io) FROM (SELECT *,WEEK(date_io) FROM a1) a11 GROUP BY WEEK(date_io),prod_id,color_id,size,store_id

select store_id as '门店',prod_id as '款号',color_id as '颜色',size as '尺码' ,WEEK(date_io) as '周类' ,sum(quant_io) as '库存量' FROM (SELECT *,WEEK(date_io) FROM a1) a11 GROUP BY store_id,prod_id,color_id,size,WEEK(date_io)



SELECT *,WEEK(date_io) FROM a1