在SELECT语句中使用HAVING和AS时无法识别列

Question

我收到一条错误消息，说HAVING子句中的total_calories不是有效的列：

SELECT type, SUM(calories) AS total_calories FROM exercise_logs
GROUP BY type
HAVING total_calories > 150;

有什么想法为什么会这样？谢谢。

Answer 1

您需要使用汇总列。别名只能按顺序使用或子查询

SELECT type, SUM(calories) AS total_calories FROM exercise_logs
GROUP BY type
HAVING SUM(calories) > 150;