Mysql 计算有多少行具有相同的值,但如果ID不同,则将其分开计算
我的问题是Mysql 计算有多少行具有相同的值,但如果ID不同,则将其分开计算,mysql,sql,database,Mysql,Sql,Database,我的问题是 Select r.coupon_id, c.who_added, c.coupon_name, r.when_added From redeemed_coupons r JOIN coupon c on r.coupon_id = c.coupon_id AND c.who_added = 1 AND r.when_added BETWEEN 1602827745 AND 1613084678 ORDER BY r.when_added 当添加时,如何获得具有相同值的行的
Select r.coupon_id, c.who_added, c.coupon_name, r.when_added
From redeemed_coupons r
JOIN coupon c on r.coupon_id = c.coupon_id AND c.who_added = 1
AND r.when_added BETWEEN 1602827745 AND 1613084678 ORDER BY r.when_added
当添加时,如何获得具有相同值的行的计数,但如果优惠券id不同,则即使添加时具有相同的,
结果如下:
|coupon_id|who_added|coupon_name|when_added| total_count|
|---------|---------------------------------------------|
| 1 | 1 |Free Appe. |1602827745| 1 |
| 2 | 1 |Free Appe. |1602835586| 1 |
| 3 | 1 |10% off |1603084636| 1 |
| 4 | 1 |50% off |1603084678| 2 |
是否只需要使用窗口函数进行计数
select r.coupon_id, c.who_added, c.coupon_name, r.when_added,
count(*) over (partition by r.coupon_id, r.when_added) as cnt
from redeemed_coupons r join
coupon c
on r.coupon_id = c.coupon_id and
c.who_added = 1 and
r.when_added BETWEEN 1602827745 AND 1613084678
order by r.when_added ;
编辑:
在旧版本的MySQL中,可以使用相关子查询:
select r.coupon_id, c.who_added, c.coupon_name, r.when_added,
(select count(*)
from redeemed_coupons r2 join
coupon c2
on r2.coupon_id = c2.coupon_id and
c2.who_added = 1 and
r2.when_added BETWEEN 1602827745 AND 1613084678
where r2.when_added = r.when_added
)
from redeemed_coupons r join
coupon c
on r.coupon_id = c.coupon_id and
c.who_added = 1 and
r.when_added BETWEEN 1602827745 AND 1613084678
order by r.when_added ;
请注意,这比使用窗口函数效率低得多。错误代码:1064。您的SQL语法有错误;检查与您的MySQL服务器版本对应的手册,以获得正确的语法,将near'(当添加时按r分区)用作第行的赎回优惠券r连接优惠券c'中的cnt2@JeremyPaul . . . 这个查询需要MySQL 8.0,但我的活动实例是MySQL 8.0。21@JeremyPaul . . . 我没有看到语法中有明显的错误。@JeremyPaul。MySQL可能要求correlation子句位于WHERE
子句中。这是我通常会说的,所以我更新了答案。请参阅: