如何解决MySQL计算多个SUM变量
我想计算2 sum()我尝试过查询,如下所示,但它运行很慢。有什么更好的想法吗?
SELECT customer,SUM(CASE WHEN book_day BETWEEN '2020-01-01' AND '2020-01-31'
THEN pax+free
ELSE 0
END) AS January,SUM(CASE WHEN book_day BETWEEN '2020-02-01' AND '2020-02-31'
THEN pax+free
ELSE 0
END) AS February,( SUM(CASE WHEN book_day BETWEEN '2020-01-01' AND '2020-01-31'
THEN pax+free
ELSE 0
END) +
SUM(CASE WHEN book_day BETWEEN '2020-02-01' AND '2020-02-31'
THEN pax+free
ELSE 0
END) ) AS total
FROM rezervations
我如何使像January + February as total
这样的简单
解决方法
将BETWEEN '2020-01-01' AND '2020-02-29'
保留在where子句中。
确保book_day列上有索引
SELECT customer,SUM(CASE WHEN book_day BETWEEN '2020-01-01' AND '2020-01-31' THEN pax+free ELSE 0 END) as January,SUM(CASE WHEN book_day BETWEEN '2020-02-01' AND '2020-02-29' THEN pax+free ELSE 0 END) as February,(SUM(CASE WHEN book_day BETWEEN '2020-01-01' AND '2020-02-29' THEN pax+free ELSE 0 END) ) as total
FROM rezervations
WHERE
book_day BETWEEN '2020-01-01' AND '2020-02-29'
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。