Question

从普通sql更改查询时遇到问题（注意：我不使用AR而是续集）

这样可行：

Post.fetch(
    "SELECT
      COUNT(*) as count, HOUR(created_at) as date, class_type
    FROM
      tours t
    WHERE
      t.created_at Between ? and ?
    GROUP BY hour(t.created_at), flavor", @range_begins, @range_ends
    ).all

它返回预期的数组。但这并不是：

Post.select("COUNT(*) as count, HOUR(created_at) as date, class_type")
    .where(created_at: @basic_range)
    .group_by("HOUR(created_at), flavor")
    .all

但是在控制台中（最后没有.all）从中生成的查询看起来很好（为了更好的阅读而格式化）：

<Sequel::Mysql2::Dataset:
"SELECT
  'COUNT(*) as count, HOUR(created_at) as date, class_type'
FROM
  `posts`
WHERE
  ((`created_at` >= '2014-05-01 00:00:00') AND (`created_at` <= '2014-05-01 23:59:59')) 
GROUP BY
  'HOUR(created_at), flavor'">

添加＆＃34; .all＆＃34;最后返回一个如下所示的数组：

[#<Tour @values={:"COUNT(*) as count, HOUR(created_at) as date, class_type"=>"COUNT(*) as count, HOUR(created_at) as date, class_type"}>]

我错过了什么？在此先感谢您的帮助

Answer 1

使用where函数编写查询时，最后不需要编写.all，默认情况下会提供与查询参数匹配的所有结果。你只需要这样做：

Post.select("COUNT(*) as count, HOUR(created_at) as date, class_type")
    .where(created_at: @basic_range)
    .group_by("HOUR(created_at), flavor")

无法在数据集上调用.all

1 个答案: