2017-07-26 116 views
-1

这是我的问题;更新重复记录,保留记录(Min)(日期)相同

我运行此查询,并得到那些拥有“FirstTimeBooking” = 1多行13469个用户:

Select CustUserId, COUNT(CustUserId) 
FROM Bookings with (nolock) 
WHERE FirstTimeBooking = 1 
GROUP BY CustUserId 
HAVING COUNT(CustUserId) > 1 
ORDER BY COUNT(CustUserId) DESC 

我需要更新所有的这些记录,对于每一行设置FirstTimeBooking = 0,除了闵( BookingDate)为每个用户(这是实际的FirstTimeBooking)。任何帮助将不胜感激。

+0

对需求的一种改变;我需要更新所有记录,为每个用户设置FirstTimeBooking = 0,每个用户的PER STPT除了Min(BookingDate),他们所在的PER STORE。 即, (用户可以在多个商店中有FirstTimeBooking,但不是每个商店的多个FirstTimeBookings) – akaWizzmaster

回答

1

我试图保持它的简单,并留在你的语法:

CREATE TABLE Bookings 
(
CustUserID int 
,FirstTimeBooking int 
,BookingDate datetime 
) 

INSERT INTO Bookings VALUES 
(1, 1, '20170101') 
,(1, 1, '20170101') -- Duplicate on same date 
,(2, 1, '20170201') 
,(2, 1, '20170301') -- On a second date 
,(3, 1, '20170401') 

UPDATE a 
SET FirstTimeBooking = 0 
FROM Bookings as a 
LEFT OUTER JOIN (
    -- Only CustUserID 1 and 2 
    SELECT CustUserID, min(BookingDate) as BookingDate 
    FROM Bookings 
    WHERE FirstTimeBooking = 1 
    GROUP BY CustUserID 
    HAVING COUNT(*) > 1 
) as b 
on a.CustUserID = b.CustUserID 
and a.BookingDate = b.BookingDate 
WHERE b.BookingDate IS NULL -- only where the first booking date has not been found in subquery 

-- Still got the Problem with CustUserID 
SELECT * 
FROM Bookings 
WHERE CustUserID = 1 

UPDATE b 
set FirstTimeBooking = 0 
FROM (
SELECT *, ROW_NUMBER() OVER (PARTITION BY CustUserID ORDER BY CustUserID) As Rown 
FROM Bookings as b 
WHERE FirstTimeBooking = 1 
) as b 
WHERE Rown = 2 

-- This is now also solved 
SELECT * 
FROM Bookings 
WHERE CustUserID = 1 

也许你没有两个完全相同的BookingDates,但我加入这个以防万一。

Regards tgr

+0

如果您想要按店铺执行此操作,只需将商店添加到分组中B-) – tgr