给定时间段内每天的2个最大日期之间的日期差异

Question

I'm trying to write a sql query to return the difference between a closing time and the final sale of the day for a given location, per day.

The DB schema is something like:

Store_Closing_table(storeCloseTime, storeId) store_sale_table(saleTime, storeID)

I've written the following(pseudo code):

select max(storeCloseTime), 
max(saleTime), datediff(mi, max(saletime), 
max(storeCloseTime)) as timeDifference, storeID 
from store_closing_table a
inner join store_sale_table b
on a.storeid = b.storeid
group by storeid, convert(date, saletime), convert(date, storeCloseTime)

Which returns the time difference between the final sale of the day and the store's closing time, but only for the most recent date(ie the max date).

I'm not sure how to get the max sale date per day and the max store closing time per day(there are situations where the store 'closes' more than once in a day) and then get the datediff between the two.

Any suggestions would be appreciated.

EDIT: I modified the query to include group by clauses, which gets me closer, but I'm getting the difference between each store sale and each store closing time.

Ie store has 3 sales over 3 days. I'm getting close 1 - sale a, close 1 - sale b, close 1 - sale c, close 2 - sale a, close 2 -sale b, close 2 - sale c, close 3 - sale a, close 3 - sale b, close 3 - sale c.

Any ideas?

Answer 1

please try this.

WITH cte
AS ( 
       select StoreID,
              CONVERT(DATE, storeCloseTime) AS [Date], 
              max(storeCloseTime) as storeCloseTime,
              max(saleTime) as SaleTime,
         FROM Store_closing_table AS a
         JOIN Store_sale_table AS b ON a.storeid = b.storeid
        GROUP BY StoreID, CONVERT(DATE, storeCloseTime)
    )
       SELECT StoreID, [Date], StoreCloseTime, SaleTime
              datediff(mi, saletime, storeCloseTime) as timeDifference