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我有一个名为Answer
的模型与has_one Question
关联。 Question
有dimension_id, possible_answers
我有以下查询通过自定义字段的Ruby ActiveRecord查询总和
Answer.joins(:question).select(:dimension_id,"(CAST(answers.answer AS FLOAT)/(length(possible_answers))) AS satisfaction").where(:created_at => date_from..date_to)
我想组由dimension_id和总和满意的结果,为了得到每个维度的满意度,但如果我不.group(:dimension_id).sum(:satisfaction)
我得到的错误PG::UndefinedColumn: ERROR: column "satisfaction" does not exist
我应该如何总结满意度以获得理想的结果? 谢谢
(dimension_id是个问题)。如果我这样做,我得到:PG :: GroupingError:错误:列“answers.answer”必须出现在GROUP BY子句中或用于聚合函数中 LINE 1:SELECT questions.dimension_id,(CAST(answers.answer AS FLOAT – marimaf