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

姓名，Total_runs，平均

听起来很简单，但对我来说唯一的问题是。在板球中，平均值不是总和（运行）/计数（*）它是总和（运行）/ how_out不是'不出'的局数的计数

有人可以告诉我如何写一个这样的查询吗？

由于显而易见的原因，我写的查询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

sql专家可以帮帮我吗？

由于

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

我认为你需要一个子选择：

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

Answer 3

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

mysql查询计算板球击球手的平均值

3 个答案: