多表联合查询后去重复数据后重新插入第一张表解决办法

select goods_id,goods_type,goods_name,in_buy_price,ROUND(sum(in_total_price)/sum(in_amount),2),count(*) from in_warehouse_detail
group by goods_id,goods_type,goods_name
order by goods_id,goods_type,goods_name

　　查询结果如下：



另一张关联表【通过goods表的goods_Id和in_warehouse_detail表的goods_id关联】

select goods_Id,goods_name,goods_sel_price,goods_buy_price from goods

希望实现效果
①根据主外键关联将in_warehouse_detail查询到的平均值【ROUND(sum(in_total_price)/sum(in_amount),2)】列数据更新到goods表的goods_buy_price 列
②查询in_warehouse_detail表in_buy_price 和 ROUND(avg(in_buy_price),2)这两列不同值 的数据
③查询goods表goods_sel_price 列和in_warehouse_detail表 ROUND(avg(in_buy_price),2)这两列不同值 的数据

后来自己琢磨出来点东西 觉得得使用临时表来处理 查询当前要做的事情后整合发现

select goods_Id,goods_name,goods_sel_price,goods_buy_price from goods

select g.goods_Id,g.goods_name,g.goods_type,g.goods_sel_price,g.goods_buy_price
,a.junjia  from goods g,avg_prices a
where g.goods_Id = a.goods_id
and g.goods_sel_price != a.junjia

将上面的查询结果塞入临时表

DROP TABLE IF EXISTS avg_prices;

create table avg_prices as
select goods_id,goods_type,goods_name,in_buy_price,
ROUND(sum(in_total_price)/sum(in_amount),2) as 'junjia',count(*) from scm.in_warehouse_detail
group by goods_id,goods_type,goods_name
order by goods_id,goods_type,goods_name;

查询生成的临时表里的数据

select * from     avg_prices

那么解决的问题就变成了 如何 将第一张表里junjia字段根据id 条件批量更新到第二张表goods表内goods_buy_price字段值

通过个人不断测试终于实现

多亏 沉沦启发我语句

update a.junjia  from goods g,avg_prices a set g.goods_sel_price = a.junji
where g.goods_Id = a.goods_id

实现语句如下 可加个定时器 每日执行 就能解决实时均价这个难题

 DROP TABLE IF EXISTS avg_prices;

create table avg_prices as
select goods_id,goods_type,goods_name,in_buy_price,
ROUND(sum(in_total_price)/sum(in_amount),2) as 'junjia',count(*) from scm.in_warehouse_detail
group by goods_id,goods_type,goods_name
order by goods_id,goods_type,goods_name;

源码

---------如果当前数据库里面存在 均价临时表 则删除掉---------
DROP TABLE IF EXISTS avg_prices;
---------创建均价临时表并将查询结果填充入临时表---------
create table avg_prices as
select goods_id,goods_type,goods_name,in_buy_price,
ROUND(sum(in_total_price)/sum(in_amount),2) as 'junjia',count(*) from scm.in_warehouse_detail
group by goods_id,goods_type,goods_name
order by goods_id,goods_type,goods_name;
---------根据ID为关联 批量更新goods表
update avg_prices a,goods g set  g.goods_buy_price = a.junjia where
g.goods_Id = a.goods_id
and g.goods_sel_price != a.junjia ;

库存也可这样尝试 批量更新goods表