Using MariaDB and trying to see if I can get pull original rankings for each row of a table based on the create date.
For example, imagine a scores table that has different scores for different users and categories (lower score is better in this case)
id
leaderboardId
userId
score
submittedAt ↓
rankAtSubmit
9
15
555
50.5
2022-01-20 01:00:00
2
8
15
999
58.0
2022-01-19 01:00:00
3
7
15
999
59.1
2022-01-15 01:00:00
3
6
15
123
49.0
2022-01-12 01:00:00
1
5
15
222
51.0
2022-01-10 01:00:00
1
4
14
222
87.0
2022-01-09 01:00:00
1
5
15
555
51.0
2022-01-04 01:00:00
1
The "rankAtSubmit" column is what I'm trying to generate here if possible.
I want to take the best/smallest score of each user+leaderboard and determine what the rank of that score was when it was submitted.
My attempt at this failed because in MySQL you cannot reference outer level columns more than 1 level deep in a subquery resulting in an error trying to reference t.submittedAt in the following query:
SELECT *, (
SELECT ranking FROM (
SELECT id, RANK() OVER (PARTITION BY leaderboardId ORDER BY score ASC) ranking
FROM scores x
WHERE x.submittedAt <= t.submittedAt
GROUP BY userId, leaderboardId
) ranks
WHERE ranks.id = t.id
) rankAtSubmit
FROM scores t
Instead of using RANK(), I was able to accomplish this by with a single subquery that counts the number of users that have a score that is lower than and submitted before the given score.
SELECT id, userId, score, leaderboardId, submittedAt,
(
SELECT COUNT(DISTINCT userId) + 1
FROM scores t2
WHERE t2.userId = t.userId AND
t2.leaderboardId = t.leaderboardId AND
t2.score < t.score AND
t2.submittedAt <= t.submittedAt
) AS rankAtSubmit
FROM scores t
What I understand from your question is you want to know the minimum and maximum rank of each user.
Here is the code
SELECT userId, leaderboardId, score, min(rankAtSubmit),max(rankAtSubmit)
FROM scores
group BY userId,
leaderboardId,
scorescode here
Related
I'm trying to figure out how to Select a specific number of rows from a MySQL table based on WHERE clause. I have a table with 10 dummy users, I want to get 2 previous and 2 next users of specific user with their ranks.
user_id | points
==================
10 200
4 130
2 540
13 230
15 900
11 300
3 600
17 110
20 140
1 430
5 800
I achieved adding a column for ranking like:
user_id | points | rank
===========================
15 900 1
5 800 2
3 600 3
2 540 4
1 430 5
11 300 6
13 230 7
10 200 8
20 140 9
4 130 10
17 110 11
But the problem is that I want only 5 rows. Suppose I'm retrieving data for user with user_id = 11. The output should look like this:
user_id | points | rank
===========================
2 540 4
1 430 5
11 300 6
13 230 7
10 200 8
where user_id = 11 is in the centre with 2 rows above and 2 below. I have tried nesting UNIONS and SELECT statements but nothing seems to work properly.
Here's a suggestion if you're on MySQL 8+:
WITH cte AS (
SELECT user_id, points,
ROW_NUMBER() OVER (ORDER BY points DESC) AS Rnk
FROM mytable)
SELECT cte2.user_id,
cte2.points,
cte2.Rnk
FROM cte cte1
JOIN cte cte2
ON cte1.user_id=11
AND cte2.Rnk >= cte1.Rnk-2
AND cte2.Rnk <= cte1.Rnk+2
Using common table expression (cte) then do a self join with condition of user_id=11 as base to get the Rnk value of -2 and +2.
Demo fiddle
Since you're on older MySQL version, here's what I can suggest:
SET #uid := 11;
SET #Rnk := (SELECT Rnk
FROM
(SELECT user_id, points,
#r := #r+1 AS Rnk
FROM mytable
CROSS JOIN (SELECT #r := 0) r
ORDER BY points DESC) v
WHERE user_id = #uid);
SELECT user_id, points, Rnk
FROM
(SELECT user_id, points,
#r := #r+1 AS Rnk
FROM mytable
CROSS JOIN (SELECT #r := 0) r
ORDER BY points DESC) v
WHERE Rnk >= #Rnk-2
AND Rnk <= #Rnk+2;
If you will only use user_id as base, then the only part here you need to change is the SET #uid. The remaining queries are just fulfilling your condition of getting two positions above and below the rank retrieved according to the user_id. The base query in SET #Rnk is the same as the base query for the last one. The idea is to assign #Rnk variable with Rnk position of user_id=11 then use it in WHERE condition for the last query.
I'm not aware if there's any online fiddle still using MySQL 5.1 but here's probably the closest version to it, MySQL 5.5 demo fiddle.
I have a table where each quiz ID is repeated multiple times. there is a date in front of each quiz id in each row. I want to select entire row for each quiz ID where date is latest with user. The date format is mm/dd/YYYY.
Sample -
USER_ID Quiz_id Name Date Marks .. .. ..
1 2 poly 4/3/2020 27
1 2 poly 4/3/2019 98
1 4 moro 4/3/2020 09
2 5 cat 4/12/2015 87
2 4 moro 4/3/2009 56
2 6 PP 4/3/2011 76
3 2 poly 4/3/2020 12
3 2 poly 5/3/2020 09
3 7 dog 4/3/2011 23
I want result look like this:Result
USER_ID Quiz_id Name Date Marks .. .. ..
1 2 poly 4/3/2020 27
1 4 moro 4/3/2020 09
2 5 cat 4/12/2015 87
2 4 moro 4/3/2009 56
2 6 PP 4/3/2011 76
3 2 poly 5/3/2020 09
3 7 dog 4/3/2011 23
You can use rank function to get the desired result:
Demo
SELECT A.* FROM (
SELECT A.*, RANK() OVER(PARTITION BY USER_ID,QUIZ_ID, NAME ORDER BY DATE DESC) RN FROM
Table1 A ORDER BY USER_ID) A WHERE RN = 1 ORDER BY USER_ID, QUIZ_ID;
I don't have MySQL installed so you will need to test and report back. The general idea is to identify the row of interest using max and a group by (table t). As the Date column appears to be text column (MySQL uses the format YYYY-MM-DD for dates) you will need to convert it to a date with str_to_date() so you can use the max() aggregate function. Finally, join with the original table (here table t2 to do the date conversion), as only the aggregate column(s) and columns named in the group by are well defined (in table t1), i.e.:
select USER_ID, Quiz_id, Date, Marks from (
select USER_ID, Quiz_id, max(str_to_date(Date, '%m/%d/%Y')) as Date2 from quiz group by 1, 2
) as t natural join (
select *, str_to_date(Date, '%m/%d/%Y') Date2 from Quiz
) as t2;
I don't recall off-hand but Date might be reserved word, in which case you will need to quote the column name, or ideally rename said column to use a better name.
Also, the original table is not in 3rd normal form as Quiz_id depends on Name. Quiz_id, as implied, should be a foreign key to a lookup table that holds the Name.
I'm trying to get the total number of levels gained or lost from this sort of table:
id name level timestamp
1 Rex 15 10:25
2 Rex 15 10:26
3 Rex 15 10:27
4 Rex 14 10:28
5 Rex 13 10:29
6 Rex 13 10:30
7 Rex 13 10:31
8 Rex 13 10:29
9 Xer 44 10:30
10 Xer 44 10:31
11 Xer 45 10:32
12 Xer 45 10:33
13 Xer 45 10:34
Currently I'm running
SELECT id, name, level, timestamp, MAX(level) - MIN(level) AS gained
FROM log
GROUP BY name
But the problem with this query is that both gained and lost levels will count as gained. It would be perfect if I could get a negative int in the gained column if the user has lost levels
The output I want from the data above is:
id name level timestamp gained
8 Rex 13 10:29 -2
13 Xer 45 10:34 1
If you need to respect the timeline, then try something like this:
SELECT MAX(id) id, name,
( SELECT level FROM log l0 WHERE l.name = l0.name ORDER BY timestamp DESC LIMIT 1 ) level,
MAX(timestamp) timestamp,
-- last entry for the name
( SELECT level FROM log l1 WHERE l.name = l1.name ORDER BY timestamp DESC LIMIT 1 ) -
-- first entry for the name
( SELECT level FROM log l2 WHERE l.name = l2.name ORDER BY timestamp ASC LIMIT 1 ) gained
FROM log l
GROUP BY name
I used LAG in as subquery to get the changes and then summed those changes in an outer sub-query. To get the last row I uses yet another query to find the max time for each name. Maybe not the most efficient query but it works
SELECT l.id, l.name, l.level, l.timestamp, sg.gain
FROM log l
JOIN (SELECT name, SUM(gain) gain
FROM (SELECT name, level - COALESCE(LAG(level) OVER w, level) as gain
FROM log
WINDOW w AS (PARTITION BY name ORDER BY timestamp)) as g
GROUP BY name) as sg ON sg.name = l.name
JOIN (SELECT name, MAX(time) max_t
FROM log
GROUP BY name) mt ON mt.name = l.name AND mt.max_t = l.time
I have the following table:
person_index score year
3 76 2003
3 86 2004
3 86 2005
3 87 2006
4 55 2005
4 91 2006
I want to group by person_index, getting the average score difference between consecutive years, such that I end up with one row per person, indicating the average increase/decrease:
person_index avg(score_diff)
3 3.67
4 36
So for person with index 3 - there were changes over 3 years, one was 10pt, one was 0, and one was 1pt. Therefore, their average score_diff is 3.67.
EDIT: to clarify, scores can also decrease. And years aren't necessarily consecutive (one person might not get a score at a certain year, so could be 2013 followed by 2015).
Simplest way is to use LAG(MySQL 8.0+):
WITH cte AS (
SELECT *, score - LAG(score) OVER(PARTITION BY person_index ORDER BY year) AS diff
FROM tab
)
SELECT person_index, AVG(diff) AS avg_diff
FROM cte
GROUP BY person_index;
db<>fiddle demo
Output:
+---------------+----------+
| person_index | avg_diff |
+---------------+----------+
| 3 | 3.6667 |
| 4 | 36.0000 |
+---------------+----------+
If the scores only increase -- as in your example -- you can simply do:
select person_id,
( max(score) - min(score) ) / nullif(max(year) - min(year) - 1, 0)
from t
group by person_id;
If they do not only increase, it is a bit trickier because you have to calculate the first and last scores:
select t.person_id,
(tmax.score - tmin.score) / nullif(tmax.year - tmin.year - 1, 0)
from (select t.person_id, min(year) as miny, max(year) as maxy
from t
group by person_id
) p join
t tmin
on tmin.person_id = p.person_id and tmin.year = p.miny join
t tmax
on tmax.person_id = p.person_id and tmax.year = p.maxy join
I have the following data
user_id days date
88 2 2013-08-25
88 4 2013-08-23
88 18 2013-08-5
88 1 2013-08-4
88 2 2013-08-2
73 11 2013-08-2
299 4 2013-08-2
12 983 2013-08-2
I'm trying to get all recent rows (order by DATE desc) for a specific user_id , until the SUM of days column is bigger than X. For example in this case if X=7 I would get the three first rows with SUM(days)=24.
Try this. Here you will use a local variable that will count the sums in the subquery.
select
user_id,
days,
date
from
(
select
user_id,
days,
date,
#sum_days := #sum_days + days as sum_days
from
myTable
order by
date desc
) t
cross join (select #sum_days := 0) const -- resetting your #sum_days var.
where
sum_days < X -- fill a number in for X here.