SQL保持运行计数,在内部Join之后

问题描述 投票:3回答:3

我正在使用本地mysql服务器,并且有两个表。

表A:

ID | Name 
1    Joe
2    Bob
3    John

表B:

ID |    DATE    |  Name_ID | Point
1    2010-01-01       1       1
2    2011-01-01       1       1
3    2013-01-01       1      -1
4    2010-01-01       2      -1
5    2012-01-01       2      -1
6    2013-01-01       2      -1
7    2014-01-01       2       1

对于表A中的每个ID,我正在尝试获取

  1. 最大日期和
  2. 他们的积分的连续计数。 (日期和点在表B中)。

想要的结果:

Name | Latest_Date | Point_total
John      NULL         NULL
Joe     2013-01-01      1
Bob     2014-01-01     -2

到目前为止,我有这个查询:

SELECT DISTINCT a.Name, b.Date, SUM(b.point) OVER (PARTITION BY b.Name_ID) Point_total FROM 
TableA a 
LEFT OUTER JOIN TableB b 
ON a.ID = b.Name_ID 
INNER JOIN  (
SELECT b.Name_ID, MAX(b.Date) Latest_Date 
FROM TableB b GROUP BY b.Name_ID ) m 
ON (m.Latest_Date = b.Date or (b.Date is NULL)) AND 
(b.Name_ID = m.Name_ID OR (b.Name_ID is NULL)) 
ORDER BY Name_ID;

结果表确实输出了正确的最大日期,但是运行总计仅考虑了具有最大日期的条目点。

我在这里想念什么?

mysql sql group-by sum max
3个回答
2
投票

这看起来像聚合:

SELECT a.Name, MAX(b.Date), SUM(b.point) as Point_total
FROM TableA a LEFT OUTER JOIN
     TableB b 
     ON a.ID = b.Name_ID 
GROUP BY a.name

2
投票

这是一个聚合查询:

select a.name, max(b.date) latest_date, sum(b.point) point_total
from a
left join b on b.name_id = a.id
group by a.id, a.name

0
投票
SELECT A.Name, MAX(B.Date) as Max_Date, SUM(b.point) as Total_Points
FROM TableA as A
    LEFT JOIN TableB as B 
    ON A.ID = B.Name_ID 
GROUP BY A.name
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