having a mysql table with multiple records belonging many different users like this:
id score
1 , 50
1 , 75
1 , 40
1, 20
2 , 85
2 , 60
2 , 20
i need to get the rank of each id but after finding the sum of their score;
the rank should be the same if the total score for each player is the same.
this gives me the total for each player:
select id,sum(score) as total from table_scores group by id order by total desc;
is it posssible to find the sum like above and use it to rank the players in one query?
Something big missing from the accepted answer. The rank needs to be bumped after a tie. If you've got 2 tied for 3rd place, there is no 4th place.
The following query is an adjustment of the accepted SQL to account for this and reset the rank variable (#r in the query) to match the row value. You can avoid the extra addition in the CASE/WHEN but initializing #row to 1 instead of 0 but then the row value is off by 1 and my OCD won't let that stand even if row number is not valuable.
select
id, total,
CASE WHEN #l=total THEN #r ELSE #r:=#row + 1 END as rank,
#l:=total,
#row:=#row + 1
FROM (
select
id, sum(score) as total
from
table_scores
group by
id
order by
total desc
) totals, (SELECT #r:=0, #row:=0, #l:=NULL) rank;
You can rank rows using variables:
select
id, total,
CASE WHEN #l=total THEN #r ELSE #r:=#r+1 END as rank,
#l:=total
FROM (
select
id, sum(score) as total
from
table_scores
group by
id
order by
total desc
) totals, (SELECT #r:=0, #l:=NULL) rank;
Please see it working here.
i find one more way to this problem... This one is based on JOIN clause
SET #rank = 0;
SELECT t1.id, t1.score, t2.rank
FROM (SELECT id, SUM(score) as score
FROM table_scores GROUP BY id ORDER BY score Desc) AS t1
INNER JOIN
(SELECT x.score, #rank:=#rank + 1 as rank FROM
(SELECT DISTINCT(SUM(score)) AS score
FROM table_scores
GROUP BY id ORDER BY score DESC) AS x) AS t2
ON t1.score = t2.score
Here is SQL Fiddle: http://sqlfiddle.com/#!9/2dcfc/16
P.S. it's interesting to see there is more then one way to solve a problem...
Related
I have a table of exam results. I need to get the record of a specific participant and get his/her ranking too.
for example, the participant with the participant_id 15 must have the ranking 3 amongst the total 4 records. so the result i am looking for would be:
id: 1
exam_id: 3
participant_id: 15
score: 343.23
ranking: 3
I know I can get the record and get the ranking through some PHP code, but I wonder if this is possible with Mysql queries.
I googled but did not really come up with a good solution. Any answer is highly appreciated!
This is the row_number function in postgresql and other databases which unfortunately isn't present in mysql.
This article http://www.mysqltutorial.org/mysql-row_number/ explains how to emulate it in mysql
To adapt the example from it
SET #row_number = 0;
SELECT
(#row_number:=#row_number + 1) AS rank, id, participant_id,exam_id, score
FROM
exams
LIMIT 5;
Following query will give you the required result
select t2.id,t2.exam_id,t2.exam_id,t2.participant_id,t2.score,t2.ranking from
(SELECT t.id,t.exam_id,t.participant_id,t.score,(#num:=#num+1) AS
ranking FROM table1 t cross join (SELECT #num:=0) AS dummy
ORDER BY t.score desc)as t2 where t2.participant_id=15;
You can run a query to create a separate table of results and then add condition to get the rank of required participant.
here is the query you can try
SELECT * FROM (SELECT re.*, #curRow := #curRow + 1 AS rank
FROM results re JOIN (SELECT #curRow := 0) r
WHERE 1 ORDER BY re.`score` DESC) AS tablea
WHERE participant_id=15
here is the result
id exam_id participant_id score rank
1 3 15 343.23 3
I am having trouble writing a query for the following problem. I have tried some existing queries but cannot get the results I need.
I have a results table like this:
userid score timestamp
1 50 5000
1 100 5000
1 400 5000
1 500 5000
2 100 5000
3 1000 4000
The expected output of the query is like this:
userid score
3 1000
1 1000
2 100
I want to select a top list where I have n best scores summed for each user and if there is a draw the user with the lowest timestamp is highest. I really tried to look at all old posts but could not find one that helped me.
Here is what I have tried:
SELECT sum(score) FROM (
SELECT score
FROM results
WHERE userid=1 ORDER BY score DESC LIMIT 3
) as subquery
This gives me the results for one user, but I would like to have one query that fetches all in order.
This is a pretty typical greatest-n-per-group problem. When I see those, I usually use a correlated subquery like this:
SELECT *
FROM myTable m
WHERE(
SELECT COUNT(*)
FROM myTable mT
WHERE mT.userId = m.userId AND mT.score >= m.score) <= 3;
This is not the whole solution, as it only gives you the top three scores for each user in its own row. To get the total, you can use SUM() wrapped around that subquery like this:
SELECT userId, SUM(score) AS totalScore
FROM(
SELECT userId, score
FROM myTable m
WHERE(
SELECT COUNT(*)
FROM myTable mT
WHERE mT.userId = m.userId AND mT.score >= m.score) <= 3) tmp
GROUP BY userId;
Here is an SQL Fiddle example.
EDIT
Regarding the ordering (which I forgot the first time through), you can just order by totalScore in descending order, and then by MIN(timestamp) in ascending order so that users with the lowest timestamp appears first in the list. Here is the updated query:
SELECT userId, SUM(score) AS totalScore
FROM(
SELECT userId, score, timeCol
FROM myTable m
WHERE(
SELECT COUNT(*)
FROM myTable mT
WHERE mT.userId = m.userId AND mT.score >= m.score) <= 3) tmp
GROUP BY userId
ORDER BY totalScore DESC, MIN(timeCol) ASC;
and here is an updated Fiddle link.
EDIT 2
As JPW pointed out in the comments, this query will not work if the user has the same score for multiple questions. To settle this, you can add an additional condition inside the subquery to order the users three rows by timestamp as well, like this:
SELECT userId, SUM(score) AS totalScore
FROM(
SELECT userId, score, timeCol
FROM myTable m
WHERE(
SELECT COUNT(*)
FROM myTable mT
WHERE mT.userId = m.userId AND mT.score >= m.score
AND mT.timeCol <= m.timeCol) <= 3) tmp
GROUP BY userId
ORDER BY totalScore DESC, MIN(timeCol) ASC;
I am still working on a solution to find out how to handle the scenario where the userid, score, and timestamp are all the same. In that case, you will have to find another tiebreaker. Perhaps you have a primary key column, and you can choose to take a higher/lower primary key?
Query for selecting top three scores from table.
SELECT score FROM result
GROUP BY id
ORDER BY score DESC
LIMIT 3;
Can you please try this?
SELECT score FROM result GROUP BY id ORDER BY score DESC, timestamp ASC LIMIT 3;
if 2 users have same score then it will set order depends on time.
You can use a subquery
SELECT r.userid,
( SELECT sum(r2.score)
FROM results r2
WHERE r2.userid = r.userid
ORDER BY score DESC
LIMIT 3
) as sub
FROM result r
GROUP BY r.userid
ORDER BY sub desc
You should do it like this
SELECT SUM(score) as total, min(timestamp) as first, userid FROM scores
GROUP BY userid
ORDER BY total DESC, first ASC
This is way more efficient than sub queries. If you want to extract more fields than userid, then you need to add them to the group by.
This will of cause not limit the number of scores pr user, which indeed seems to require a subquery to solve.
Sorry for posting another question about mysql ranking but all questions and answers which I already looked didn't help me....
I have mysql table of user points. User can have more results. My goal is to get max result from user and its rank.
CREATE TABLE results
(`user_id` int, `points` int);
INSERT INTO results VALUES
(1,10),
(2,20),
(3,20),
(4,30),
(4,60),
(5,5),
(1,80);
So upper solution would be:
rank | user_id | points
1 1 80
2 4 60
3 3 20
3 2 20
4 5 5
The following query does the trick:
SET #rank=0;
SET #points=0;
SELECT #rank := IF(#points = a.points, #rank, #rank + 1) AS rank, a.user_id, #points := a.points AS points
FROM (
SELECT user_id, MAX(points) as points
FROM results
GROUP BY user_id
) a
ORDER BY a.points DESC;
I have also created an SQLFiddle of it so you can see that it works: http://sqlfiddle.com/#!2/7ba2f/12
Use a user defined variable to produce the rank when selecting from an aggregated aliased query that calculates the maximum for each user:
select
(#rank := ifnull(#rank, 0) + 1) as rank,
user_id,
points
from (select
user_id,
max(points) as points
from results
group by 1
order by 2 desc) x
FYI, a UDV starts out life as null, hence the ifnull() call.
There are several rank posts out there but I have yet to see one dealing with when the results are paginated and when the ranking criteria (in this case: points) is equal to the previous user. I have tried a few of the pre-existing examples but none have worked.
I have a table called "users" with the column "id". I also have a table called "points" with the columns "user_id" and "amount".
I need:
1.) Users with duplicate sum of points to have the same rank
Points Table
user_id amount
1 10
2 20
1 5
3 20
3 -5
4 5
Rank should be
rank user_id total
1 2 20
2 1 15
2 3 15
3 4 5
2.) Needs to maintain the ranking from one page to another so the rank has to be gathered in the query and not the resulting PHP.
3.) Display ALL users not just ones with rows in the points table because some users have 0 points and I want to display them last.
Right now I'm just listing the users in order of their points but their rank is not gathered because it wasn't working.
$getfanspoints = mysql_query("SELECT DISTINCT id,
(SELECT SUM(amount) AS points FROM points WHERE points.user_id = users.id) AS points
FROM users
ORDER BY points DESC LIMIT $offset, $fans_limit", $conn);
I've read these solutions and none have worked.
[Roland's Blog][1]
[How to get rank based on SUM's][2]
[MySQL, get users rank][3]
[How to get rank using mysql query][4]
and a few others whose link I can't find right now.
Any suggestions?
[EDIT]
I used ypercube's bottom answer.
SELECT COUNT(*) AS rank
, t.user_id
, t.total
FROM
( SELECT user_id
, SUM(amount) AS total
FROM points
GROUP BY user_id
) AS t
JOIN
( SELECT DISTINCT
SUM(amount) AS total
FROM points
GROUP BY user_id
) AS dt
ON
t.total <= dt.total
GROUP BY t.user_id
ORDER BY rank
, user_id
But the above may be really slow with a big table and points awarded often. It might be really better to have just this and calculate the ranks in your application code:
SELECT users.id AS user_id
, SUM(amount) AS total
FROM
users
LEFT JOIN
points
ON points.user_id = users.id
GROUP BY users.id
ORDER BY total DESC
, user_id
This will work, too (edited, to work with the users table and with OFFSET):
SELECT *
FROM
( SELECT
#rank := #rank + (#t <> total) AS rank
, user_id
, #t := total AS total
FROM
( SELECT users.id AS user_id
, COALESCE(SUM(amount),0) AS total
FROM users
LEFT JOIN points
ON users.id = points.user_id
GROUP BY users.id
) AS o
CROSS JOIN
( SELECT #rank := 0, #t := -999999
) AS dummy
ORDER BY total DESC
, user_id
) tmp
LIMIT x OFFSET y
I have a table very similar to the one below. p1 and p2 on the table refer to id of player on an another table.
id score p1 p2 date
-- ----- -- -- ----
1 12 1 2 2011.10.21
2 23 3 4 2011.10.22
3 21 1 3 2011.10.23
4 35 5 1 2011.10.24
5 11 2 3 2011.10.25
What I want to do is the get the player id (p1 or p2) with highest score. My solution is something like select sum(score) but I can't form a query because a player may appear in both p1 or p2 columns.
Also a bigger problem is when I want to sort scores from highest to lowest. I dont know what to do. How can I sum and sort a score if I need to group to separate columns? The result I want is similar to this output:
pID score times_played
--- ----- ------------
1 68 3
3 55 3
5 35 1
2 23 2
4 23 1
Is my database design flawed? If there is a more intelligent way I'd like to know. Should I need seperate single queries so I can merge them on PHP or something?
Any help would be appreciated.
Cheers.
PS: I couldnt think a nice subject. Feel free to edit.
You can put the players in one column as so:
select id, score, p1 as player, date from yourtable
union all
select id, score, p2 as player, date from yourtable
You now have players in one column. You can do this to get the score sum for all players
select sum(score), player from (
select id, score, p1 as player, date from yourtable
union all
select id, score, p2 as player, date from yourtable
) group by player
Now, you say that you also want to know how many times the player played and sort them in descending order:
select sum(score), player, count(*) as timesPlayed from (
select id, score, p1 as player, date from yourtable
union all
select id, score, p2 as player, date from yourtable
) group by player order by sum(score) desc
Try this to get players with highest score (disregarding ties)
select id,p1,p2
from table t1
join (select max(score) as MaxS) xx on xx.MaxS = t1.Score
limit 1
To get player total score, try this
select Player as pID,Sum(tot) as Score, count(*) as TimesPlayed
from
(
select p1 as Player,sum(score) as Tot
from table
group by p1
union all
select p2,sum(score)
from table
group by p2
) xx
Group by xx.Player
order by Score desc
Alternatively to using UNION (ALL) on the table, you could try something like this:
SELECT
CASE p.PlayerNumber WHEN 1 THEN t.p1 ELSE t.p2 END AS pID,
SUM(t.score) AS score,
COUNT(*) AS times_played
FROM atable t
CROSS JOIN (SELECT 1 AS PlayerNumber UNION ALL SELECT 2) p
GROUP BY
pID /* this is probably MySQL-specific; most, if not all, other major
database systems would require repeating the entire pID expression here, i.e.
GROUP BY
CASE p.PlayerNumber WHEN 1 THEN t.p1 ELSE t.p2 END
*/
ORDER BY
score DESC,
times_played DESC /* this is based on your result set;
you might want to omit it or change it to ASC */
UPDATE, in an answer to a question in the comments: joining the result set to the user table:
SELECT
`user`.*, /* you should probably specify
the necessary columns explicitly */
totals.score,
totals.times_played
FROM `user` u
INNER JOIN (
SELECT
CASE p.PlayerNumber WHEN 1 THEN t.p1 ELSE t.p2 END AS pID,
SUM(t.score) AS score,
COUNT(*) AS times_played
FROM atable t
CROSS JOIN (SELECT 1 AS PlayerNumber UNION ALL SELECT 2) p
GROUP BY
pID
) totals ON user.id = totals.pID
ORDER BY
totals.score DESC,
totals.times_played DESC