[英]MySQL procedure - Getting to work
这是我编写的程序,用于找出每个客户每天购买的前10件商品。
这是我尝试过的第一次PL / SQL操作,它没有实现我期望的功能。
我使用的逻辑是接受每个客户对我感兴趣的开始日期,结束日期和最高的“ x”销售额。 然后遍历唯一的客户表cust_table
并找到每个客户每天的前x个。
我可以要求指导以使它正常工作吗?
CREATE PROCEDURE `at _the _top`( in stDate date, in edDate date, in lim int)
BEGIN
DECLARE done INT DEFAULT FALSE;
DECLARE cust TEXT;
DECLARE custNames CURSOR FOR SELECT CUSTOMER FROM cust_table;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
OPEN custNames;
read_loop: LOOP
FETCH custNames INTO cust;
IF done THEN
LEAVE read_loop;
END IF;
WHILE(stDate <= edDate) DO
#insert into top_cust(EVE_DATE,CUST_NAME,ITEM_ID,ITEMS_PURCHASED) (select EVE_DATE, CUST_NAME, ITEM_ID, SUM(ITEM_BUNDLE_SIZE) as ITEMS_PURCHASED_TOTAL from cust_sales_hist where EVE_DATE = stDate and CUST_NAME = cust group by EVE_DATE, ITEM_ID order by ITEMS_PURCHASED_TOTAL desc limit lim);
SELECT concat('Custome - ', cust);
SELECT CONCAT('Start Date - ', stDate);
SELECT CONCAT('End date - ', edDate);
SELECT CONCAT('Limit - ', lim);
SELECT
EVE_DATE,
CUST_NAME,
ITEM_ID,
SUM(ITEM_BUNDLE_SIZE) AS ITEMS_PURCHASED_TOTAL
FROM
cust_sales_hist
WHERE
EVE_DATE = stDate
AND CUST_NAME = cust
GROUP BY
EVE_DATE ,
ITEM_ID
ORDER BY
ITEMS_PURCHASED_TOTAL DESC
LIMIT
LIM;
SET stDate = date_add(stDate, INTERVAL 1 DAY);
end WHILE;
END LOOP;
CLOSE custNames;
END
实际上,您根本不需要存储过程。 相反,您可以使用一个使用user-defined variables
的单个select
语句?
select eve_date, cust_name, item_id, sum(item_bundle_size) sumsize
from (
select eve_date, cust_name, item_id, item_bundle_size,
@rn := if(@prevDate=eve_date and @prevItem=item_id, @rn + 1,
if (@prevDate:=eve_date,
if (@prevItem:=item_id, 1, 1)
, 1)
) rn
from cust_sales_hist cross join
(select @rn:=0, @prevDate:=null, @prevItem:=null) t
where cust_name = 'Cust 1' and
eve_date between '2016-08-01' and '2016-08-02'
order by eve_date, item_id
) t
where rn <= 2
group by eve_date, cust_name, item_id
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