Mysql2 ::錯誤：操作數應包含1列（S）

Question

這條線在我的控制器：

Mysql2::Error: Operand should contain 1 column(s): SELECT `feedbacks`.* FROM `feedbacks` WHERE (reviewer_id = 1, reviewee_id = 10, strength_id = 0) LIMIT 1 

Answer 1

我覺得你的SQL：

@feedback = Feedback.where("reviewer_id = ?, reviewee_id = ?, strength_id = ?", current_user.id, @report_for.id, @context).first 

，當我嘗試顯示@feedback.something產生這個錯誤是錯的，試試這個

@feedback = Feedback.where("reviewer_id = ? and reviewee_id = ? and strength_id = ?", current_user.id, @report_for.id, @context).first