Question

我正在努力根据下表编写一个查询，该查询应该获取位置的错误记录（其中BadRec = 1）以及该位置上的前3条记录（Max），包括错误记录;

TranDate                Location BadRec
======================= ======== ======
2010-08-25 00:00:00.000  STN-2     0
2010-08-26 00:00:00.000  STN-2     1
2010-08-27 00:00:00.000  STN-1     1
2010-08-28 00:00:00.000  STN-1     0
2010-08-28 00:00:00.000  STN-2     1
2010-08-29 00:00:00.000  STN-1     0
2010-08-30 00:00:00.000  STN-1     1
2010-08-31 00:00:00.000  STN-1     0
2010-09-01 00:00:00.000  STN-1     0

这是预期的Put;

TranDate                Location BadRec comments
======================= ======== ====== ========
2010-08-30 00:00:00.000  STN-1     1    <- Bad record on STN-1
2010-08-29 00:00:00.000  STN-1     0    <- First Previous record
2010-08-28 00:00:00.000  STN-1     0    <- Second Previous record
2010-08-27 00:00:00.000  STN-1     1    <- Third Previous record (Previous include bad rec)
2010-08-28 00:00:00.000  STN-2     1    <- Bad record on STN-2
2010-08-26 00:00:00.000  STN-2     1    
2010-08-25 00:00:00.000  STN-2     0    
2010-08-27 00:00:00.000  STN-1     1    <- Bad record on STN-1,No previous record for this 
2010-08-26 00:00:00.000  STN-2     1    <- Bad record on STN-2
2010-08-25 00:00:00.000  STN-2     0

这可以使用单个查询来编写吗？使用CTE ??结束（分区......）??任何帮助都非常感谢。注意：我在SQL 2005机器上;

Answer 1

这样做你想要的吗？

SELECT TranDate, Location, BadRec
FROM
    (
    SELECT pr.TranDate, pr.Location, pr.BadRec,
        ROW_NUMBER() OVER (PARTITION BY r.TranDate ORDER BY pr.TranDate DESC) AS SEQUENCE
    FROM Records r
    JOIN Records pr ON r.Location = pr.Location
                    AND r.TranDate >= pr.TranDate
    WHERE r.BadRec = 1
    ) x
WHERE SEQUENCE <= 4

SQL Query查找以前的记录

1 个答案: