Mysql 从数百万条记录中选择排名
我会向SO寻求帮助,因为我找不到类似的情况、问题/帖子 假设我有数百万条记录,列是 用户id-假设其记录范围为1到1000000 名称-假设它还记录了多达20个字母 分数-0到100,假设其也已记录 日期-记录的日期时间戳 假设我知道我的用户id是什么,我想知道我自己的排名 我还想获得排名上下的其他10个用户记录,比如说我的排名是100,我还想选择排名在我排名上90到99,排名下101到110的用户。 若不同的用户按记录的日期具有相同的分数顺序排名,则较早的记录具有较高的排名。 可能吗? 假设所有记录都是唯一的,并且没有设置索引 我知道如何排序Mysql 从数百万条记录中选择排名,mysql,sql,innodb,Mysql,Sql,Innodb,我会向SO寻求帮助,因为我找不到类似的情况、问题/帖子 假设我有数百万条记录,列是 用户id-假设其记录范围为1到1000000 名称-假设它还记录了多达20个字母 分数-0到100,假设其也已记录 日期-记录的日期时间戳 假设我知道我的用户id是什么,我想知道我自己的排名 我还想获得排名上下的其他10个用户记录,比如说我的排名是100,我还想选择排名在我排名上90到99,排名下101到110的用户。 若不同的用户按记录的日期具有相同的分数顺序排名,则较早的记录具有较高的排名。 可能吗? 假设所
SELECT * FROM record order by score
但是这会让我选择所有的记录,在不选择每个记录的情况下选择特定数据的实际方法是什么
以下是我想要实现的目标
user_id | name | score | date | rank |
------------------------------------------------------------------
12341 | namep | 90 | 2017-01-01 04:02:36 | 90 |
45341 | nameo | 88 | 2017-01-02 00:05:45 | 91 |
24341 | namex | 88 | 2017-01-03 00:11:15 | 92 |
26867 | namec | 83 | 2017-01-03 01:41:23 | 93 |
19156 | nameb | 81 | 2017-01-03 02:36:45 | 94 |
74973 | namem | 79 | 2017-01-03 04:07:55 | 95 |
23134 | namek | 78 | 2017-01-04 02:01:25 | 96 |
21424 | namet | 77 | 2017-01-04 02:41:33 | 97 |
19534 | nameg | 77 | 2017-01-04 02:56:15 | 98 |
74912 | namez | 75 | 2017-01-04 04:07:55 | 99 |
my_uid | my_name | 75 | 2017-01-04 13:07:45 | 100 |
86766 | namen | 75 | 2017-01-04 14:21:47 | 101 |
67976 | namey | 74 | 2017-01-04 16:22:23 | 102 |
34676 | nameu | 74 | 2017-01-04 17:33:32 | 103 |
86236 | namei | 73 | 2017-01-04 18:11:09 | 104 |
98636 | nameo | 73 | 2017-01-04 19:21:47 | 105 |
14326 | namep | 73 | 2017-01-04 20:33:22 | 106 |
45333 | namet | 72 | 2017-01-04 20:44:12 | 107 |
33323 | namer | 72 | 2017-01-04 21:34:26 | 108 |
11322 | namee | 71 | 2017-01-04 22:51:54 | 109 |
86633 | namew | 70 | 2017-01-04 22:55:33 | 110 |
好的,这是我现在得到的,很抱歉,我没有提到任何关于不使用union或UNIONALL的内容,我不能在我的项目中使用它
但无论如何,这是我的疑问
我使用了multi_查询函数
$sql = "SELECT score, date FROM table_name WHERE user_id=your_user_id;" //assume you already know your user_id
$sql .= "SELECT name, score, date FROM table_name WHERE score >= your_score ORDER BY score, date LIMIT 10;"; //to get 10 rows that have greater or same score of your score order by date, earlier date is higher rank if score is the same with other user.
$sql .= "SELECT name, score, date table_name WHERE score <= your_score DESC, date ASC LIMIT 10"; //select score less than or equal to my score order by score and date
我的问题是,当使用多个查询时,它仍然与执行3个不同的查询相同,因为我有3个查询,如何将其组合为一个?不使用union或union all?
在第三个查询中,如何从数据设置起点?在MySQL中,view就像其他语言中的函数一样
CREATE VIEW rankall AS SELECT * FROM record ORDER BY score;
SELECT * FROM rankall
WHERE rank > (SELECT rank FROM rankall WHERE user_id = ID) - 11
AND rank < (SELECT rank FROM rankall WHERE user_id = ID) + 11;
这是基本思想,但不能保证上述代码能正常工作:试试这个
SELECT user_id, name, score FROM record
WHERE score BETWEEN
CONVERT((SELECT score FROM record WHERE user_id = (SELECT user_id FROM record WHERE score = '100') ), INTEGER) - 10
AND
CONVERT((SELECT score FROM record WHERE user_id = (SELECT user_id FROM record WHERE score = '100') ), INTEGER) + 10
ORDER BY score DESC, date DESC
这是一个可行的方法,但也有一些问题需要解决。这将获得所选用户的任意一方得分以及该用户的排名。然后按分数排序并计算排名。这确实正常工作,但如果所选用户是得分最高/最低的用户,则会出现问题。可以对其进行排序,但不确定实际数据是否可用。但我会给你一些想法 这是使用用户id 86474作为您感兴趣的用户id,并且每侧仅获得1-只是为了适合您提供的测试数据:-
SELECT user_id,
name,
score,
date,
def_rank - (@ranking := @ranking -1) AS rank
FROM
(
SELECT *
FROM
(
(SELECT r1.user_id,
r1.name,
r1.score,
r1.date,
sub0.def_rank
FROM record r1
INNER JOIN record r2 ON r2.user_id = 86476
CROSS JOIN
(
SELECT COUNT(*) def_rank
FROM record r1
INNER JOIN record r2 ON r2.user_id = 86476
WHERE r1.score >= r2.score
) sub0
WHERE r1.score >= r2.score
ORDER BY score ASC
LIMIT 2)
UNION
(SELECT r1.user_id,
r1.name,
r1.score,
r1.date,
sub0.def_rank
FROM record r1
INNER JOIN record r2 ON r2.user_id = 86476
CROSS JOIN
(
SELECT COUNT(*) def_rank
FROM record r1
INNER JOIN record r2 ON r2.user_id = 86476
WHERE r1.score >= r2.score
) sub0
WHERE r1.score <= r2.score
ORDER BY score DESC
LIMIT 2)
) sub97
ORDER BY score
) sub1
CROSS JOIN
(
SELECT @ranking := 2
) sub2
我终于得到了我想要的,所以我只回答我自己的问题
SELECT score, date FROM rank WHERE uid=your_user_id; //your score and date recorded
SELECT (count(*) + 1) AS rank FROM rank WHERE score > your_score OR (score = your_score AND date < date of your score recorded); //your rank
SELECT * FROM rank WHERE score > your_score OR (score = your_score AND date < date of your score recorded) ORDER BY score ASC, date DESC LIMIT 10; //10 users above my rank, in your output you have to reverse the order
SELECT * FROM rank WHERE score < your_score OR (score = your_score AND date > date of your score recorded) ORDER BY score DESC, date ASC LIMIT 10; //10 users below my rank
感谢其他回复的用户:可能与@Takarii重复感谢您的回复,我将查看此帖子!查看MariaDB中可用的窗口功能。感谢您的回复!我忘了提到我必须使用MySQL,但我会看看窗口功能。@Takarii在我的项目中,我不能使用union或union all,可能吗?当然,上面的代码不起作用。排名本身不会突然出现在你的视野中。谢谢你的回复!对于初学者来说,它看起来非常复杂,我只知道基本知识,但我会看一看,谢谢你的想法!
CREATE VIEW rankall AS SELECT * FROM record ORDER BY score;
SELECT * FROM rankall
WHERE rank > (SELECT rank FROM rankall WHERE user_id = ID) - 11
AND rank < (SELECT rank FROM rankall WHERE user_id = ID) + 11;
SELECT user_id, name, score FROM record
WHERE score BETWEEN
CONVERT((SELECT score FROM record WHERE user_id = (SELECT user_id FROM record WHERE score = '100') ), INTEGER) - 10
AND
CONVERT((SELECT score FROM record WHERE user_id = (SELECT user_id FROM record WHERE score = '100') ), INTEGER) + 10
ORDER BY score DESC, date DESC
SELECT user_id,
name,
score,
date,
def_rank - (@ranking := @ranking -1) AS rank
FROM
(
SELECT *
FROM
(
(SELECT r1.user_id,
r1.name,
r1.score,
r1.date,
sub0.def_rank
FROM record r1
INNER JOIN record r2 ON r2.user_id = 86476
CROSS JOIN
(
SELECT COUNT(*) def_rank
FROM record r1
INNER JOIN record r2 ON r2.user_id = 86476
WHERE r1.score >= r2.score
) sub0
WHERE r1.score >= r2.score
ORDER BY score ASC
LIMIT 2)
UNION
(SELECT r1.user_id,
r1.name,
r1.score,
r1.date,
sub0.def_rank
FROM record r1
INNER JOIN record r2 ON r2.user_id = 86476
CROSS JOIN
(
SELECT COUNT(*) def_rank
FROM record r1
INNER JOIN record r2 ON r2.user_id = 86476
WHERE r1.score >= r2.score
) sub0
WHERE r1.score <= r2.score
ORDER BY score DESC
LIMIT 2)
) sub97
ORDER BY score
) sub1
CROSS JOIN
(
SELECT @ranking := 2
) sub2
SELECT score, date FROM rank WHERE uid=your_user_id; //your score and date recorded
SELECT (count(*) + 1) AS rank FROM rank WHERE score > your_score OR (score = your_score AND date < date of your score recorded); //your rank
SELECT * FROM rank WHERE score > your_score OR (score = your_score AND date < date of your score recorded) ORDER BY score ASC, date DESC LIMIT 10; //10 users above my rank, in your output you have to reverse the order
SELECT * FROM rank WHERE score < your_score OR (score = your_score AND date > date of your score recorded) ORDER BY score DESC, date ASC LIMIT 10; //10 users below my rank