I have a table with game scores, allowing multiple rows per account id: scores (id, score, accountid). I want a list of the top 10 scorer ids and their scores.
Can you provide an sql statement to select the top 10 scores, but only one score per account id?
Thanks!
select username, max(score) from usertable group by username order by max(score) desc limit 10;
First limit the selection to the highest score for each account id.
Then take the top ten scores.
SELECT TOP 10 AccountId, Score
FROM Scores s1
WHERE AccountId NOT IN
(SELECT AccountId s2 FROM Scores
WHERE s1.AccountId = s2.AccountId and s1.Score > s2.Score)
ORDER BY Score DESC
Try this:
select top 10 username,
max(score)
from usertable
group by username
order by max(score) desc
PostgreSQL has the DISTINCT ON clause, that works this way:
SELECT DISTINCT ON (accountid) id, score, accountid
FROM scoretable
ORDER BY score DESC
LIMIT 10;
I don't think it's standard SQL though, so expect other databases to do it differently.
SELECT accountid, MAX(score) as top_score
FROM Scores
GROUP BY accountid,
ORDER BY top_score DESC
LIMIT 0, 10
That should work fine in mysql. It's possible you may need to use 'ORDER BY MAX(score) DESC' instead of that order by - I don't have my SQL reference on hand.
I believe that PostgreSQL (at least 8.3) will require that the DISTINCT ON expressions must match initial ORDER BY expressions. I.E. you can't use DISTINCT ON (accountid) when you have ORDER BY score DESC. To fix this, add it into the ORDER BY:
SELECT DISTINCT ON (accountid) *
FROM scoretable
ORDER BY accountid, score DESC
LIMIT 10;
Using this method allows you to select all the columns in a table. It will only return 1 row per accountid even if there are duplicate 'max' values for score.
This was useful for me, as I was not finding the maximum score (which is easy to do with the max() function) but for the most recent time a score was entered for an accountid.
Related
I'm trying to score people in Microsoft Access based on the count they have for a particular category.
There are 7 possible categories a person can have against them, and I want to assigned each person a score from 1-7, with 1 being assigned to the highest scoring category, 7 being the lowest. They might not have an answer for every category, in which case that category can be ignored.
The aim would be to have an output result as shown in this image:
I've tried a few different things, including partition over and joins, but none have worked. To be honest I think I'm way off the mark with the queries I've been trying. I've tried to write the code in SQL from scratch, and used query builder.
Any help is really appreciated!
As you for an email can have duplicated counts, you will need two subqueries for this:
SELECT
Score.email,
Score.category,
Score.[Count],
(Select Count(*) From Score As T Where
T.email = Score.email And
T.[Count] >= Score.[Count])-
(Select Count(*) From Score As S Where
S.email = Score.email And
S.[Count] = Score.[Count] And
S.category > Score.category) AS Rank
FROM
Score
ORDER BY
Score.email,
Score.[Count] DESC,
Score.category;
For categories with equal Count values for the same email, the following will rank the records alphabetically descending by Category name (since this is what is shown in your example):
select t.email, t.category, t.count,
(
select count(*) from YourTable u
where t.email = u.email and
((t.count = u.count and t.category <= u.category) or t.count < u.count)
) as rank
from YourTable t
order by t.email, t.count desc, t.category desc
Change both references of YourTable to the name of your table.
SELECT MAX(Score)
FROM Students
WHERE Score < (SELECT MAX(Score) FROM Students);
the above query works perfectly and fetches the record that has 2nd highest score, whereas the query mentioned below does not fetch anything
SELECT *
FROM Students
WHERE Score < (SELECT MAX(Score) FROM Students);
here Students is the table from which I want to fetch all the details of that record which has 2nd highest score in the entire table.
I want that 2nd query should get executed, thanks in advance for helping me out.
I have not used any database, I'm simply trying out these queries in w3schools.
With standard SQL, this is typically solved using window functions:
select *
from (
select *, dense_rank() over (order by score desc) as rnk
from students
) t
where rnk = 2;
The above is ANSI standard SQL and works on all modern DBMS.
How about ordering and getting the first record returned using LIMIT:
SELECT *
FROM Students
WHERE Score < (SELECT MAX(Score) FROM Students)
ORDER BY Score DESC
LIMIT 1;
I need to perform TREAMMEAN in Access, which does not have this function.
In a table I have many Employees, each has many records.
I need to TRIMMEAN Values for each Employee separately.
Following queries perform TOP 10 percent for all records:
qry_data_TOP10_ASC
qry_data_TOP10_DESC
unionqry_TOP10_ASCandDESC
qry_data_ALL_minus_union_qry
After that, I can use Avg (Average).
But I don't know how to do it for each employee.
Visualization:
Note:
This question is edited to simplify problem.
You don't really give information in your pseudo code about your data fields but using your example that DOES have basic field information I can suggest the following should work as you described
It assumes field1 is your unique record ID - but you make no mention of which fields are keys
SELECT AVG(qry_data.field2) FROM qry_data WHERE qry_data.field1 NOT IN
(SELECT * FROM
(SELECT TOP 10 PERCENT qry_data.field1, qry_data.field2
FROM qry_data
ORDER BY qry_data.field2 ASC)
UNION
(SELECT TOP 10 PERCENT qry_data.field1, qry_data.field2
FROM qry_data
ORDER BY qry_data.field2 DESC)
)
This should give you what you want, the two sub-queries should correlate the TOP 10s (ascending and descending) for every employee. The two NOT INs should then remove those from the Table1 records and then you group the Employees and Average the Scores.
SELECT Table1.Employee, AVG(Table1.Score) AS AvgScore
FROM Table1
WHERE ID NOT IN
(
SELECT TOP 10 ID
FROM Table1 a
WHERE a.Employee = Table1.Employee
ORDER BY Score ASC, Employee, ID
)
AND ID NOT IN
(
SELECT TOP 10 ID
FROM Table1 b
WHERE b.Employee = Table1.Employee
ORDER BY Score DESC, Employee, ID
)
GROUP BY Table1.Employee;
I am trying to distinct and then find the count of the teams a player played for in any single season and number of teams he played for. This is tripping me up and ofcourse i have a sample down below(2nd) one. The first ones is my failed attempt
SELECT o.id,o.year,COUNT(DISTINCT(o.team)) b JOIN
(SELECT id, year, team FROM batting
GROUP BY id,year,team
ORDER BY id DESC
LIMIT 25) o
0.id =b.id;
SELECT id, year, team FROM batting
GROUP BY id,year,team
ORDER BY id DESC
LIMIT 25;
produces
IGNORE the ^A, i think they represent either space or comma, just column seperatpr
Get the count of teams for each player for each year and order by the count desc,get the 1 row
SELECT id, year, COUNT(DISTINCT(team)) FROM batting
GROUP BY id,year
ORDER BY COUNT(DISTINCT(team)) DESC
LIMIT 1;
Not sure how to ask a followup on SO, but this is in reference to an earlier question:
Fetch one row per account id from list
The query I'm working with is:
SELECT *
FROM scores s1
WHERE accountid NOT IN (SELECT accountid FROM scores s2 WHERE s1.score < s2.score)
ORDER BY score DESC
This selects the top scores, and limits results to one row per accountid; their top score.
The last hurdle is that this query is returning multiple rows for accountids that have multiple occurrences of their top score. So if accountid 17 has scores of 40, 75, 30, 75 the query returns both rows with scores of 75.
Can anyone modify this query (or provide a better one) to fix this case, and truly limit it to one row per account id?
Thanks again!
If you're only interested in the accountid and the score, then you can use the simple GROUP BY query given by Paul above.
SELECT accountid, MAX(score)
FROM scores
GROUP BY accountid;
If you need other attributes from the scores table, then you can get other attributes from the row with a query like the following:
SELECT s1.*
FROM scores AS s1
LEFT OUTER JOIN scores AS s2 ON (s1.accountid = s2.accountid
AND s1.score < s2.score)
WHERE s2.accountid IS NULL;
But this still gives multiple rows, in your example where a given accountid has two scores matching its maximum value. To further reduce the result set to a single row, for example the row with the latest gamedate, try this:
SELECT s1.*
FROM scores AS s1
LEFT OUTER JOIN scores AS s2 ON (s1.accountid = s2.accountid
AND s1.score < s2.score)
LEFT OUTER JOIN scores AS s3 ON (s1.accountid = s3.accountid
AND s1.score = s3.score AND s1.gamedate < s3.gamedate)
WHERE s2.accountid IS NULL
AND s3.accountid IS NULL;
select accountid, max(score) from scores group by accountid;
If your RDBMS supports them, then an analytic function would be a good approach particularly if you need all the columns of the row.
select ...
from (
select accountid,
score,
...
row_number() over
(partition by accountid
order by score desc) score_rank
from scores)
where score_rank = 1;
The row returned is indeterminate in the case you describe, but you can easily modify the analytic function, for example by ordering on (score desc, test_date desc) to get the more recent of two matching high scores.
Other analytic functions based on rank will achieve a similar purpose.
If you don't mind duplicates then the following would probably me more efficient than your current method:
select ...
from (
select accountid,
score,
...
max(score) over (partition by accountid) max_score
from scores)
where score = max_score;
If you are selecting a subset of columns then you can use the DISTINCT keyword to filter results.
SELECT DISTINCT UserID, score
FROM scores s1
WHERE accountid NOT IN (SELECT accountid FROM scores s2 WHERE s1.score < s2.score)
ORDER BY score DESC
Does your database support distinct? As in select distinct x from y?
This solutions works in MS SQL, giving you the whole row.
SELECT *
FROM scores
WHERE scoreid in
(
SELECT max(scoreid)
FROM scores as s2
JOIN
(
SELECT max(score) as maxscore, accountid
FROM scores s1
GROUP BY accountid
) sub ON s2.score = sub.maxscore AND s2.accountid = s1.accountid
GROUP BY s2.score, s2.accountid
)