Question

此查询从活动表中获取每月所有活动玩家的数量：

SELECT
  date_trunc('month', createdat) as month,
  count(distinct playerid) as play_all
FROM
    activity
group by month
order by 1

此查询获取每月玩“蜜蜂”游戏的玩家人数：

SELECT
  date_trunc('month', createdat) as month,
  count(distinct playerid) as play_bee
FROM
    activity
where gamename = 'bee'    
group by month
order by 1

我如何获得每月玩“蜜蜂”游戏的玩家百分比？

Answer 1

这可能有效：

SELECT
  DATE_TRUNC('month', createdat) AS month,
  COUNT(DISTINCT playerid) AS play_all,
  COUNT(DISTINCT CASE WHEN gamename = 'bee' THEN playerid END) AS play_bee,
  100. * COUNT(DISTINCT CASE WHEN gamename = 'bee' THEN playerid END)
       / COUNT(DISTINCT playerid) AS percent_play_bee,
FROM
    activity
group by month
order by 1

它利用以下事实：CASE WHEN gamename = 'bee' THEN playerid END如果playerid将返回gamename = 'bee，但如果不是则将返回NONE。（我不确定NONE响应是否会包含在COUNT(DISTINCT..)中，因此它可能会被1禁用。）

基本上，CASE是针对每一行进行单独评估的。然后，将值设为DISTINCT，然后对其进行计数。

每月玩此游戏的玩家百分比Redshift

1 个答案: