postgre数据库如何实现行转列

表结构及数据

 

  select logdatetime,sum(login) as login,sum(logo) as logo

from(

  SELECT date(logdatetime) AS "logdatetime", case logfrom when "login‘ then COUNT(id) else 0 end AS "login",

  case logfrom when ‘logo‘ then COUNT(id) else 0 end AS "logo"

  FROM "log" WHERE date(logdatetime) >= ‘2014-11-04‘ AND date(logdatetime) <= ‘2014-11-05‘ GROUP BY "logdatetime", "logfrom"

  ) T

  GROUP BY "logdatetime"

  ORDER BY "logdatetime" ASC

PGSQL多行聚合，PGSQL多行合并为一行，PGSQL多行合并

《PostgreSQL 多行变一行》

《PostgreSQL官方文档-聚集函数》

array_agg(distinct(字段名)) 去重后可以获得拼接唯一的字段

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