根据百分比值排序

Question

我有一个“真实百分比值”，使用以下公式计算：

true% = true_answers/total_answers 

其中total_answers是total_correct_answers和total_incorrect_answers的SUM。我使用以下查询来获取TRUE和FALSE答案。

SELECT 
SUM(IF(true_answer = 1, 1, 0)) AS total_correct_answers, 
SUM(IF(correct_answer != 1, 1, 0)) AS total_incorrect_answers FROM table 
WHERE date BETWEEN '$from' AND '$to'

我使用PHP使用total_correct_answers和total_incorrect_answers计算total_answers和true_percentage值，并在jqgrid中显示这些值。现在我需要根据“true％”值对列表进行排序。怎么做到这一点？我试过了

ORDER BY SUM(IF(correct_answer = 1, 1, 0))/SUM(IF(correct_answer != 1,1,0))+SUM(IF(correct_answer = 1, 1, 0)) asc 

但这是错误地排序网格。怎么办呢？