mysql过滤SELECT查询结果。

Question

我有以下查询。

step2

然后我想过滤掉NumResults，因此该表仅显示NumResults = 1的结果。

Answer 1

使用HAVING子句过滤聚合函数的结果（在您的情况下为COUNT）

SELECT COUNT(id) AS NumResults, race_date AS RaceDate, race_time AS RaceTime
FROM results 
WHere jockeys_claim = 10
GROUP BY race_date, race_time
HAVING COUNT(id) = 1
ORDER BY race_date DESC, race_time ASC