结果集a:
转换成为结果集b:
mysql中实现如下:
select a.biz_date, case when a.`event` = 'downclick' then a.uv end as downclick, case when a.`event` = 'successclick' then a.uv end as successclick, case when a.`event` = 'installsuccess' then a.uv end as installsuccessfrom a
