Mysql 按嵌套表计数排序

我有两个表

Major（majorId，label）

和

minorId（minorId，majorId）

我要返回按小调（和标签）计数排序的大调

比如：

SELECT majorId,
       label
FROM Major ma
ORDER BY
  (SELECT COUNT(*)
   FROM Minor mi
   WHERE mi.majorId=ma.majorId), label;

我想象它工作的方式是：副表按majorId分组，然后为每个majorId计算行数，然后主表按相应的计数排序，然后按标签排序。

这样如何：

SELECT majorId, label
FROM Major ma
ORDER BY (SELECT COUNT(*) FROM Minor mi WHERE mi.majorId=ma.majorId 
group by mi.majorId), label ;

这个怎么样：

SELECT majorId, label
FROM Major ma
ORDER BY (SELECT COUNT(*) FROM Minor mi WHERE mi.majorId=ma.majorId 
group by mi.majorId), label ;

---

除了分组之外，还可以使用横向连接：

SELECT majorId, label
    ,tMinor.cnt 
FROM Major AS ma 
LATERAL
(
     SELECT COUNT(*) AS cnt 
     FROM Minor AS mi 
     WHERE mi.majorId = ma.majorId
) AS tMinor 

ORDER BY cnt, label

或传统上与团队合作：

SELECT 
     majorId, label
    ,COUNT(DISTINCT mi.minorId) AS cnt 
FROM Major AS ma 

LEFT JOIN Minor AS mi 
     ON mi.majorId = ma.majorId

GROUP BY majorId, label

ORDER BY cnt, label

---

除了分组之外，还可以使用横向连接：

SELECT majorId, label
    ,tMinor.cnt 
FROM Major AS ma 
LATERAL
(
     SELECT COUNT(*) AS cnt 
     FROM Minor AS mi 
     WHERE mi.majorId = ma.majorId
) AS tMinor 

ORDER BY cnt, label

或传统上与团队合作：

SELECT 
     majorId, label
    ,COUNT(DISTINCT mi.minorId) AS cnt 
FROM Major AS ma 

LEFT JOIN Minor AS mi 
     ON mi.majorId = ma.majorId

GROUP BY majorId, label

ORDER BY cnt, label

---

你的问题是什么？你的代码看起来不错。你的问题是什么？你的代码看起来不错。