我会求助于SO,因为我找不到类似的情况,问题/帖子和我的问题
假设我有数百万条记录,则列为
user_id - 假设其记录从1到1,000,000
name - 假设它还记录了最多20个字母的字母
得分 - 0到100,假设它也记录了
日期 - 记录的日期(时间戳)
user_id | name | score | date |
------------------------------------------------
23131 | name1 | 15 | 2017-01-04 02:01:25
26824 | name2 | 63 | 2017-01-04 02:41:33
19684 | name3 | 28 | 2017-01-04 02:56:15
74937 | name4 | 01 | 2017-01-04 04:07:55
27486 | name5 | 75 | 2017-01-04 13:07:45
86476 | name6 | 56 | 2017-01-04 14:21:47
36479 | name7 | 19 | 2017-01-04 17:11:15
86752 | name8 | 38 | 2017-01-04 18:22:23
11267 | name9 | 100 | 2017-01-04 20:34:42
88763 | name10 | 89 | 2017-01-04 22:45:43
有可能吗?
假设所有记录都是唯一的,并且没有设置索引。
我知道如何对排名进行排序
SELECT * FROM record order by score
但这可以让我选择所有记录,在不选择每条记录的情况下选择特定数据的实用方法是什么?
这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,所以这就是我现在所得到的,抱歉我没有提到任何关于不使用union或union的事情,我不能在我的项目中使用它。
但无论如何这里是我的查询 我使用了“multi_query()”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
我得到这样的东西
my_uid | my_name | 75 | 2017-01-04 13:07:45 | 100 |
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 |
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 |
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?没有使用工会或工会全部? 在第3个查询中,如何从数据中设置起点?
答案 0 :(得分:0)
在MySQL中,视图就像是其他语言中的一种功能。
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;
这是基本的想法,但不能保证上面的代码能够起作用:P
答案 1 :(得分:0)
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
答案 2 :(得分:0)
可能的方法,但有些问题需要解决。这将获得所选用户的任何一方(得分明智)的记录以及该用户的等级。然后按分数命令并计算排名。这确实可以正常工作,但如果所选用户是最高/最低分数,那么会很麻烦。可以对此进行排序,但不确定实际数据是否可以使用。但是会给你一些想法。
这是使用用户ID 86474作为你感兴趣的那个,并且只是为了得到1 - 只是为了适合你给出的测试数据: -
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
答案 3 :(得分:0)
我终于得到了我想要的东西,所以我将回答我自己的问题
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:)