将两个条件与不同的MySQL组合在一起

Question

我可以用这两个条件进行一次查询吗？如果是的话，我应该挖哪个方式？

SELECT c.ID, c.DateEnd FROM conference c WHERE DateEnd = DATE_ADD(CURDATE(),INTERVAL 1 DAY)

SELECT a.ID, a.IDConf FROM application a GROUP BY a.IDConf HAVING COUNT(a.IDConf) >= 2

Answer 1

您可以使用左连接。试试这个：

SELECT c.ID, a.ID a_ID, c.DateEnd 
FROM conference c LEFT JOIN application a 
ON c.ID=a.IDConf
WHERE DateEnd=DATE(DATE_ADD(CURDATE(),INTERVAL 1 DAY))
GROUP BY c.ID, a.ID 
HAVING COUNT(a.IDConf)>=2;

有关使用联接的见解，请参阅MySQL Join Made Easy。

Answer 2

如果您只想加入/public的结果，可以在子选择中使用内部联接

HAVING COUNT(a.IDConf) >= 2