多对多关系MYSQL - 根据用户输入选择数据，例如症状

Question

我有三张桌子

我希望按症状数量匹配排序疾病，症状由最终用户输入并存储在变量$ searchSymptoms中。

我尝试跟踪查询并做了一些改动，得到了一个非常奇怪的结果。

SELECT DISTINCT ailments.ailmentName,COUNT(symptoms.symptomID) AS count 
FROM ailments LEFT JOIN jnctn_ailments_symptoms ON ailments.ailmentID = jnctn_ailments_symptoms.FK_ailmentID 
LEFT JOIN symptoms ON ailments.ailmentID = jnctn_ailments_symptoms.FK_ailmentID 
GROUP BY ailments.ailmentName ORDER BY count DESC

结果：

如果有任何答案，我将有责任。

问候

Answer 1

查询可以写成如下：

SELECT ailmentID, ailmentName, ailmentSymptomCount
FROM ailments a
     LEFT JOIN(
         SELECT FK_ailment_id, COUNT(FK_symptom_id) AS ailmentSymptomCount 
                FROM jnctn_ailments_symptoms GROUP BY FK_ailment_id
     ) temp
    ON a.ailmentID = temp.FK_ailment_id

Demo