Question

我写了这个查询：

SELECT COUNT(ProductID) AS ProNumber, userID
FROM orderLog WHERE time >= CURDATE()
GROUP BY userID ORDER BY ProNumber DESC

我想这样做：

SELECT COUNT(ProductID) AS ProNumber, userID
FROM orderLog WHERE time >= CURDATE() AND ProNumber > 1000
GROUP BY userID ORDER BY ProNumber DESC

但它不起作用。为什么？我该如何解决这个问题？

Answer 1

因为在执行WHERE子句时MySQL尚不知道您的别名ProNumber。您不应在WHERE子句

中使用列别名

如果您只想保留COUNT（*）＆gt;的记录; 1000，你应该使用HAVING子句来过滤GROUP BY后的记录：

SELECT COUNT(ProductID) AS ProNumber, userID
FROM orderLog 
WHERE time >= CURDATE() 
GROUP BY userID 
HAVING COUNT(ProductID) > 1000
ORDER BY ProNumber DESC

如果这不是您想要的，请添加说明，因为它不清楚

Answer 2

让我们试试这个： - ）

SELECT COUNT(ProductID) AS ProNumber, userID
FROM orderLog WHERE time >= CURDATE() AND ProductID> 1000
GROUP BY userID ORDER BY ProductID DESC

MySQL用于计算组的位数

2 个答案: