Question

我部署到heroku（运行PG）后出现以下错误，虽然它在本地运行正常（运行sqlite3）

ActionView::Template::Error (PGError: ERROR:  column "calendar_day" does not exist
LINE 1: ...ated_at > '2012-04-09 19:39:54.787077') AND (date(calendar_d...
                                                         ^
SELECT  date(created_at) as calendar_day, count(*) as total_checkins FROM "checkins"  WHERE (user_id = 1 AND group_id = 1 AND created_at > '2012-04-09 19:39:54.787077') AND (date(calendar_day) = '2012-05-07') GROUP BY date(created_at) LIMIT 1):
...
app/helpers/groups_helper.rb:32:in `checkin_day'

请注意，“calendar_day”不是持久表上的实际列，而是我使用AS语句动态定义的列（不确定这在技术上是什么）。相关的帮助函数如下所示。基本上，在页面顶部我调用calendar_view，稍后我将结果传递给checkin_day作为checkins参数。在这次checkin_day调用中，我遇到了错误。知道为什么这在本地工作正常但不在heroku中工作吗？

def calendar_view(member, timeperiod)
  Checkin.select("date(created_at) as calendar_day, count(*) as total_checkins").where("user_id = ? AND group_id = ? AND created_at > ?", member.member.id, member.group.id, Time.now - timeperiod.days).group("date(created_at)")
end

def checkin_day(checkins, day)
  ch = checkins.where("date(calendar_day) = ?", day).first
  return ch.total_checkins if ch
  return 0
end

Answer 1

在评估WHERE子句（选择）期间，您在查询的SELECT部分定义的内容（投影）不可用。你必须在那里再次定义它：

def checkin_day(checkins, day)
  ch = checkins.where("date(created_at) = ?", day).first
  return ch.total_checkins if ch
  return 0
end

Heroku Postgres错误：列不存在

1 个答案: