mysql, ASC 使用现有数据的一系列数字
美好的一天,我有这个查询,它按数字大的顺序排列我的数据
Good day, I have this query which arrange my data in order of higher number
SELECT username,count(*) as description
FROM products
WHERE
description LIKE '%Yes%'
or
description LIKE '%yes%'
GROUP BY username
ORDER BY description ASC
这会给我带来这个结果
username | description
a | 3
b | 1
我能够做到以上几点,问题是我应该怎么做才能做到这一点?
I'm able to do the above, question is what should I do in order to make it like this?
rank | username | description
1 | a | 3
2 | b | 1
新列,rank,它是一个固定的 1,2,3,不会随着用户名和描述名称的变化而变化.
new column, rank, which is a fixed 1,2,3 that won't change while the username and description name change.
推荐答案
我知道在使用带有 group by
的变量时有时会出现问题.我不确定这是否会影响计数变量,但它肯定会影响运行总和.更安全的方法是使用子查询:
I know there are sometimes issues when using variables with group by
. I'm not sure if this affects counting variables, but it definitely affects running sums. A safer approach is to use a subquery:
SELECT (@rn := @rn + 1) as rank, username, numdescription
FROM (SELECT p.username, count(*) as numdescription
FROM products p
WHERE description LIKE '%Yes%' or description LIKE '%yes%'
GROUP BY p.username
) p CROSS JOIN
(SELECT @rn := 0) vars
ORDER BY numdescription DESC;
请注意,我重命名了输出字段.使用相同的名称似乎令人困惑,因为一个是描述(字符串),另一个是计数(数字).
Note that I renamed the output field. Using the same name seems confusing, because one is a description (string) and the other is a count (number).
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