mysql查询来计算板球击球手的平均值

Question

我有一个mysql表，它包含这样的数据。

Name |how_out |runs 
------------------------------ 
Robin |Not out |45 
Robin |lbw  |25 
Robin |caught  |50 
Robin |caught  |0 
Robin |bowled  |30 
Robin |bowled  |0 
. 
. 
. 

我想要一个SQL查询，它返回以下列

名称，Total_runs，平均

听起来很简单，但对我来说唯一的问题是。 在板球，平均是不SUM（运行）/ COUNT（*） 它的总和（运行）/局的数字的计数，其中how_out不是“不出来”

能有一个人告诉我如何写一个这样的查询？

我写的查询出于明显原因给出了错误的平均值。 我写的查询是

Select `Name`,sum(`runs`) as 'Total_runs', Sum(`runs`)/count(*) 
From `batsman_stats` 
group by `Name` 
order by 2 desc 

请问sql专家请帮帮我吗？

感谢

Answer 1

Select `Name`,sum(`runs`) as 'Total_runs', Sum(`runs`)/sum(if(how_out <> 'Not out',1,0)) 
From `batsman_stats` 
group by `Name` 
order by 2 desc 

Answer 2

You could use a CASE statement：

SELECT Name, 
     SUM(Runs) as Total_runs, 
     SUM(Runs)/COUNT(CASE WHEN how_out <> 'Not out' THEN 1 END) as Average 
FROM batsman_stats 
GROUP BY Name 
ORDER BY SUM(Runs) DESC 

Answer 3

我想你需要一个子查询：

Select Name, sum(runs) as Total_runs, Sum(runs)/(
    select count(*) from batsman_stats b 
    where b.Name=a.Name and not b.how_out = 'Not out' 
) 
From batsman_stats a 
group by Name 
order by 2 desc