Question

我有以下查询。结果是两个coloums，oakid和max（计数（评级））。我想要的是有两列，但实际上没有max（计数（评级）），我想要与max（计数（评级））相关的评级。如何修改我的查询给我这个？

select oakid, 
  (select max(count(rating)) 
     from climbs, routes 
     where climbs.routename = routes.name 
     and climbs.climberid = oakid group by routes.rating) 
  as skill
 from climbers;

例如，如果我有“硬，硬，容易，简单，容易，中等”的评级，则最大（计数（评级））将显示“3”，因为有3个“简单”评级，但我想要它显示“容易”，而不是“3”。

Answer 1

听起来好像您希望每个oakid或climberid都有statistical mode（最常出现的）评分。 Oracle为我们提供了一个方便的功能，称为STATS_MODE：

SELECT c.climberid AS oakid, STATS_MODE(r.rating) AS skill
FROM climbs c
INNER JOIN routes r ON (c.routename = r.name)
GROUP BY c.climberid;

Answer 2

尝试以下方法：

select oakid, 
  (select rating
     from climbs, routes 
     where climbs.routename = routes.name 
     and climbs.climberid = oakid 
         group by routes.rating 
         having max(count(rating)) = count(rating)) 
  as skill
 from climbers

Oracle SQL获取与max（count（））关联的列值

2 个答案: