I have a game leaderboard comprised of 500 rows of data and I wrote a script to return that data and have no duplicate scores. However, I am getting duplicate scores returned to me. Here is my script.
SELECT DISTINCT
username, score,
FIND_IN_SET(score, (SELECT DISTINCT GROUP_CONCAT(score ORDER BY score DESC)
FROM TPS_STATS)) AS rank
FROM
TPS_STATS
ORDER BY
rank ASC
LIMIT 100;
An example of the duplicate results I am seeing is posted as an image.
If your version of MySql is 8.0 then you can use row_number():
SELECT
username,
score,
row_number() OVER (ORDER BY score desc, username) rn
FROM TPS_STATS
ORDER BY score desc, username
LIMIT 100
See the demo.
If it is lower:
select
username,
score,
(select count(*) from TPS_STATS where score > t.score) +
(select count(*) from TPS_STATS where score = t.score and username < t.username) + 1
rank
from TPS_STATS t
order by rank, username
limit 100
See the demo
Related
I currently need to order data by highest value down, and then lowest value up, in between.
My Query is close, but doesn't quite order by largest down, though it is inserting the lowest in between:
DEMO Fiddle
select users.*
from users CROSS JOIN (select #even := 0, #odd := 0) param
order by
IF(score > 1, 2*(#odd := #odd + 1), 2*(#even := #even + 1) + 1),
score DESC;
Current Results
Email Score
----- --------
foo1#gmail.com 42
foo5#gmail.com 1
foo2#gmail.com 49
foo6#gmail.com 0
foo3#gmail.com 37
foo4#gmail.com 7
foo#gmail.com 22
Desired Results
Email Score
----- --------
foo2#gmail.com 49
foo6#gmail.com 0
foo1#gmail.com 42
foo5#gmail.com 1
foo3#gmail.com 37
foo4#gmail.com 7
foo#gmail.com 22
You can achieve using MySQL but avoid such complex SQL statements as the same can be achieved using programming language very easily.
SET #totalRows := (CASE WHEN (SELECT COUNT(*) FROM users) IS NULL THEN 0 ELSE (SELECT COUNT(*) FROM users) END);
PREPARE stmt1 FROM '(SELECT t.* FROM (SELECT ROW_NUMBER() OVER (ORDER BY score DESC) AS row_num, email, score FROM users UNION ALL SELECT ROW_NUMBER() OVER (ORDER BY score ASC) AS row_num, email, score FROM users) AS t ORDER BY t.row_num, t.score DESC LIMIT 0,?)';
EXECUTE stmt1 USING #totalRows;
Here is the explanation to achieve it:
Set variable #totalRows contains total rows in users table as that many rows will be displayed as a final result set.
Used ROW_NUMBER() function of MySQL to set ordering based on SOCRE field DESCENDING and ASCENDING for another result set.
Combined both the result set using UNION ALL statement of MySQL
Add the LIMIT keyword to make sure the final result must have a total number of rows that should not exceed #totalRows variable.
As in MySQL LIMIT statement we can't pass a dynamic value at a query level. I used the approach of prepare a statement.
You can ignore row_num column I used as final result set.
Hope my solution will help you.
For MySql 8.0+ you can use ROW_NUMBER() window function:
SELECT email, score
FROM (
SELECT *,
ROW_NUMBER() OVER (ORDER BY score DESC) rn1,
ROW_NUMBER() OVER (ORDER BY score ASC) rn2
FROM users
) t
ORDER BY LEAST(rn1, rn2), rn1;
For previous versions you can simulate ROW_NUMBER() with correlated subqueries (with the cost of poor performance for large datasets):
SELECT email, score
FROM (
SELECT u1.*,
(SELECT COUNT(*) FROM users u2 WHERE u2.score > u1.score) rn1,
(SELECT COUNT(*) FROM users u2 WHERE u2.score < u1.score) rn2
FROM users u1
) t
ORDER BY LEAST(rn1, rn2), rn1;
See the demo.
I am using the below query on the above database table but unable to get the distinct value. Help will be appreciated
SELECT DISTINCT doctor_user_id, doctor_name, score, time_in_seconds FROM basket_game_master WHERE game_id='$game_id' ORDER BY score DESC, time_in_seconds ASC LIMIT $limit
The goal is to retrieve the doctor name with unique doctor_user_id who have more score with less time_in_seconds
You can use ROW_NUMBER():
SELECT doctor_user_id, doctor_name, score, time_in_seconds
FROM (SELECT bgm.*,
ROW_NUMBER() OVER (PARTITION BY doctor_user_id ORDER BY score DESC, time_in_seconds ASC) as seqnum
FROM basket_game_master bgm
WHERE game_id = ?
) mgm
WHERE seqnum = 1
ORDER BY score DESC, time_in_seconds ASC
LIMIT ?;
Note the use of ? for the parameters. Do not munge the query string with literal values! That poses a risk for SQL injections and for hard-to-debug syntax errors.
I have a table with name rating as this.
I am writing the query like this
SELECT user_id, sum(score) as score
FROM quiz_rashad.rating
group by user_id
order by score desc
then how I get rating index of the 12th user?
Thank you for helping.
Assuming, that "the 12th user" means the user with the ID 12:
In MySQL 8.0+ you can use dense_rank().
SELECT x.rating_index
FROM (SELECT r.user_id,
dense_rank() OVER (ORDER BY sum(r.score) DESC) rating_index
FROM quiz_rashad.rating r
GROUP BY r.user_id) x
WHERE x.user_id = 12;
Edit:
For MySQL 5.7 you have to use subqueries getting the distinct count of total scores greater than or equal the total score for the user with ID 12.
SELECT count(DISTINCT x.score) rating_index
FROM (SELECT r.user_id,
sum(r.score) score
FROM quiz_rashad.rating r
GROUP BY r.user_id) x
WHERE x.score >= (SELECT sum(r.score)
FROM quiz_rashad.rating r
WHERE r.user_id = 12)
We can try using LIMIT with OFFSET here:
SELECT user_id, SUM(score) AS score
FROM quiz_rashad.rating
GROUP BY user_id
ORDER BY score DESC
LIMIT 1 OFFSET 11;
This answer assumes that what you really want here is the record with the twelfth rank. It also assumes that no two users would be tied for the same score.
I need to show a ranking lists for a sport we manage.
It needs to sum up the 4 best results for each player (from a table that could have hundreds of results per player) and then sort the entire list from the player with the most points to least points.
The query below returns
ERROR 1054 (42S22): Unknown column 'r1.user_id' in 'where clause'
so I've gone off track somewhere.
SELECT r1.user_id, (
SELECT SUM(points)
FROM (
SELECT *
FROM ranking_matrix_points r2
WHERE user_id=r1.user_id
ORDER BY points DESC
LIMIT 4
) r3
) AS total_points
FROM ranking_matrix_points r1
WHERE
user.status IN('active')
GROUP BY r1.user_id
ORDER BY total_points DESC
One possible solution might be to number the rows for each user in order of points descending and then sum up the points with a rank <= 4. This might not perform very well though, and also you'll get a problem with ties (but you would have using limit too).
select user_id, sum(points) total_points
from (
select user_id, points,
(
case user_id
when #cur_user
then #row := #row + 1
else #row := 1 and #cur_user := user_id end
) as rank
from ranking_matrix_points,
(select #row := 0, #cur_user := '') r
order by user_id, points desc
) t
where rank <= 4
group by user_id;
I'm pretty sure there are better ways to do this but I can't think of any at the moment. This would have been very easy in just about any database with support for window functions, but sadly MySQL doesn't support any yet.
You don't need a double query, just
SELECT user_id, SUM(points)
FROM ranking_matrix_points
WHERE user.status in('active')
GROUP BY user_id
ORDER BY total_points DESC
LIMIT 4
or
SELECT TOP 4 user_id, SUM(points)
FROM ranking_matrix_points
WHERE user.status in('active')
GROUP BY user_id
ORDER BY total_points DESC
I have a Score table that hold user_id,score in MySql . each user has many scores . I want to get best rank of each user ?
I check a lot of solution but all of them work for table that each user has single score .
I tried this but sometimes user by min score got higher rank :
SET #rank= 0;;
SELECT Users.username, score, rank
FROM (
SELECT * , #rank := #rank +1 AS rank
FROM Scores
JOIN (
SELECT userid AS user_id2, MAX( score ) AS max_score
FROM Scores
GROUP BY user_id2
ORDER BY max_score DESC
) AS max_score_table ON max_score = Scores.score
AND Scores.userid = user_id2
) derived_table
join Users On (Users.id=derived_table.user_id2)
ORDER BY rank
LIMIT 0, 100