mysql - MYSQL 根据返回的行检索数据

Question

我正在研究一个 mysql 查询，它将根据返回的行数过滤掉某些事件。

当返回的行数为 1 时，我试图过滤掉任何支持类别，但是当返回的结果集大于 1 时，保留支持类别。

我最初有这个想法，但它似乎行不通。

SELECT stockmaster.description, SUM(salesorderdetails.quantity), stockmaster.categoryid         as qty 
FROM salesorderdetails, stockmaster 
where salesorderdetails.stkcode=stockmaster.stockid 
and orderno='5222'
group by stockmaster.description
HAVING CASE WHEN stockmaster.categoryid = 'S&M' THEN COUNT(*) >= 2 ELSE COUNT(*) = 1   END

任何帮助将不胜感激。

Answer 1

尝试这个

SELECT *
FROM
(

SELECT stockmaster.description, 
       SUM(salesorderdetails.quantity), 
       stockmaster.categoryid         as qty ,
       COUNT(*) AS count
FROM salesorderdetails, stockmaster 
where salesorderdetails.stkcode=stockmaster.stockid 
and orderno='5222'
group by stockmaster.description
HAVING CASE WHEN stockmaster.categoryid = 'S&M' 

) MAIN_DATA

WHERE MAIN_DATA.count >1