I have a table with winner and loser statistics from a game:
id winner_id loser_id
1 1 2
2 1 2
3 3 4
4 4 3
5 1 2
6 2 1
7 3 4
8 3 2
9 3 5
10 3 6
11 2 3
12 3 6
13 2 3
I want a result table where i can find the highest winning streak of every player in the game. A streak of a player is broken, when he lost a game (player_id = loser_id). It should look like:
player_id win_streak
1 3
2 2
3 4
4 1
5 0
6 0
I tried many queries with user defined variables etc. but i can't find a solution. Thanks!
SQL Fiddle : http://sqlfiddle.com/#!9/3da5f/1
Is this the same as Alex's approach; I'm not quite sure, except that it seems to have one distinct advantage.... ;-)
SELECT player_id, MAX(CASE WHEN result = 'winner' THEN running ELSE 0 END) streak
FROM
( SELECT *
, IF(player_id = #prev_player,IF(result=#prev_result,#i:=#i+1,#i:=1),#i:=1) running
, #prev_result := result
, #prev_player:=player_id
FROM
( SELECT id, 'winner' result, winner_id player_id FROM my_table
UNION
SELECT id, 'loser', loser_id FROM my_table
) x
,
( SELECT #i:=1,#prev_result = '',#prev_player:='' ) vars
ORDER
BY x.player_id
, x.id
) a
GROUP
BY player_id;
I guess you should better to do that on php (or any other language you use) side.
But just to give you some idea and as experiment and example for some unique cases (hope it could be useful somewhere)
Here is my approach:
http://sqlfiddle.com/#!9/57cc65/1
SELECT r.winner_id,
(SELECT MAX(IF(winner_id=r.winner_id,IF(#i IS NULL, #i:=1,#i:=#i+1), IF(loser_id = r.winner_id, #i:=0,0)))
FROM Results r1
WHERE r1.winner_id = r.winner_id
OR r1.loser_id = r.winner_id
GROUP BY IF(winner_id=r.winner_id, winner_id,loser_id)) win_streak
FROM ( SELECT winner_id
FROM Results
GROUP BY winner_id
) r
It returns not all ids now but only who had ever win. So to make it better, probably you have user table. If so it would simplify a query. If you have no user table you need to union all somehow users who had never win.
You are welcome if any questions.
Related
I have a query like below, it is working fine but not optimized, since it takes 1.5 sec to run. How to make this to an optimized result?
select h.keyword_id,
( select count(DISTINCT(user_id)) from history where category_id = 6
and h.keyword_id=keyword_id group by keyword_id ) as cat_6,
( select count(DISTINCT(user_id)) from history where category_id = 7
and h.keyword_id = keyword_id group by keyword_id ) as cat_7
from
history h group by h.keyword_id
History table
his_id keyword_id category_id user_id
1 1 6 12
2 1 6 12
3 1 7 12
4 1 7 12
5 2 6 13
6 2 6 13
7 2 7 13
8 3 6 13
Result:
keyword_id cat_6 cat_7
1 2 2 (unique users)
2 2 1
3 1 0
You can rewrite your query like this:
select h.keyword_id,
count(distinct if(category_id = 6, user_id, null)) as cat_6,
count(distinct if(category_id = 7, user_id, null)) as cat_7
from
history h
group by h.keyword_id
Your desired result based on the sample data is by the way false. In each keyword_id there's always just one distinct user_id.
you can see the query in action in an sqlfiddle here
For more optimization, you'd have to post the result of show create table history and the output of explain <your_query>;
I have a "resources" table that contains information about how resources of a specific weight are placed inside a territory by an user.
territory_id user_id weight
1 1 1
1 1 4
1 1 2
1 2 2
2 3 2
2 2 3
2 2 3
3 1 1
4 1 1
4 1 1
4 2 2
4 3 3
4 3 1
4 3 2
5 3 2
5 3 3
5 2 1
4 3 1
I want to calculate, for each existing territory, which user has the highest total weight of resources (and what is this value).
So this should be an expected outcome for the previous data:
territory_id best_user_id best_user_total_weight_of_resources
1 1 7
2 2 6
3 1 1
4 3 6
5 3 5
I have already tried several nested queries with SUM, MAX, GROUP BY but I really didn't find the proper way to calculate this.
I have found a lot of similiar question, but not solving this exact problem.
Any help? Thanks in advance!
EDIT:
I found out right now that the double GROUP BY (i.e. "GROUP BY territory_id, user_id") with double ORDER BY partially solves my problem, but it shows also information that I don't want (not only the best user, but each single user that placed at least one resource).
SELECT territory_id, user_id AS best_user_id, SUM( weight ) AS best_user_total_weight
FROM resources
GROUP BY territory_id, user_id
ORDER BY territory_id ASC, best_user_total_weight DESC;
You can run a first query to determine SUM(weight) for each couple (territory_id,user_id) and then run a second SELECT query on that result set to retrieve the row corresponding to max summ value:
SELECT territory_id, user_id, MAX(summ)
FROM (
SELECT territory_id, user_id, SUM(weight) AS summ
FROM resources
GROUP BY territory_id, user_id
) AS t1
GROUP BY territory_id
I'm creating a simple database which will allow me to track snooker results, producing head to head results between players. Currently I have 3 tables: (Player, Fixture, Result)
PlayerID PlayerName
1 Michael Abraham
2 Ben Mullen
3 Mark Crozier
FixtureID Date TableNo Group
1 07/12/2015 19:00:00 12 0
2 08/12/2015 12:00:00 9 0
ResultID FixtureID PlayerID FramesWon
1 1 1 3
2 1 3 1
3 2 1 2
4 2 3 5
As you can see in the Result table, Player1 has played Player3 two times, with Player1 winning the first match 3-1, and Player3 winning the second match 5-2. I would like a query which returns the total number of matches won between the two players. In this case the expected output should be:
PlayerID MatchesWon
1 1
3 1
Any help would be appreciated - I'm not even sure if this can be achieved via a query
I agree using windowing function would be best way to go if available (SQL Server for example)
Might be possible with a straight SQL method this way (given that the one having most wins in a "fixture" is the match winner)
SELECT PlayerId, FixtureID, Count(*) As MatchesWon
FROM Result r
WHERE r.Frameswon = (SELECT MAX(frameswon) FROM Result r2
WHERE
r.FixtureId = r2.FixtureId)
GROUP BY PlayerID,FixtureId
OR if can leave out the fixtureId, and filter for just the 2 players something like this one as well. with data given above should bring the sample results.
SELECT PlayerId, MatchesWon
FROM
(
SELECT FixtureID,PlayerId, Count(*) As MatchesWon
FROM Result r
WHERE r.Frameswon = (SELECT max(frameswon) FROM Result r2
WHERE
r.FixtureId = r2.FixtureId)
GROUP BY FixtureId,PlayerID
) s
WHERE
PlayerID IN (1,3)
Perhaps this would work for you:
select playerid, count(*) as matcheswon
from result as r1
where frameswon =
(
select max(frameswon)
from result as r2
where r2.fixtureid = r1.fixtureid
)
group by playerid
In a fiddle here: http://sqlfiddle.com/#!9/60821/2
This is the alternative you can try.
SELECT r.PlayerID, COUNT(r.PlayerID)
FROM (
SELECT FixtureID, MAX(FramesWon) AS FramesWon
FROM `result`
GROUP BY FixtureID
) win
INNER JOIN result r ON win.FixtureID = r.FixtureID AND win.FramesWon = r.FramesWon
GROUP By r.PlayerID
I have a table with columns similar to below , but with about 30 date columns and 500+ records
id | forcast_date | actual_date
1 10/01/2013 12/01/2013
2 03/01/2013 06/01/2013
3 05/01/2013 05/01/2013
4 10/01/2013 09/01/2013
and what I need to do is get a query with output similar to
week_no | count_forcast | count_actual
1 4 6
2 5 7
3 2 1
etc
My query is
SELECT weekofyear(forcast_date) as week_num,
COUNT(forcast_date) AS count_forcast ,
COUNT(actual_date) AS count_actual
FROM
table
GROUP BY
week_num
but what I am getting is the forcast_date counts repeated in each column, i.e.
week_no | count_forcast | count_actual
1 4 4
2 5 5
3 2 2
Can any one please tell me the best way to formulate the query to get what I need??
Thanks
try:
SELECT weekofyear(forcast_date) AS week_forcast,
COUNT(forcast_date) AS count_forcast, t2.count_actual
FROM
t t1 LEFT JOIN (
SELECT weekofyear(actual_date) AS week_actual,
COUNT(forcast_date) AS count_actual
FROM t
GROUP BY weekOfYear(actual_date)
) AS t2 ON weekofyear(forcast_date)=week_actual
GROUP BY
weekofyear(forcast_date), t2.count_actual
sqlFiddle
You have to write about 30 (your date columns) left join, and the requirement is that your first date column shouldn'd have empty week (with a count of 0) or the joins will miss.
Try:
SELECT WeekInYear, ForecastCount, ActualCount
FROM ( SELECT A.WeekInYear, A.ForecastCount, B.ActualCount FROM (
SELECT weekofyear(forecast_date) as WeekInYear,
COUNT(forecast_date) as ForecastCount, 0 as ActualCount
FROM TableWeeks
GROUP BY weekofyear(forecast_date)
) A
INNER JOIN
( SELECT * FROM
(
SELECT weekofyear(forecast_date) as WeekInYear,
0 as ForecastCount, COUNT(actual_date) as ActualCount
FROM TableWeeks
GROUP BY weekofyear(actual_date)
) ActualTable ) B
ON A.WeekInYear = B.WeekInYear)
AllTable
GROUP BY WeekInYear;
Here's my Fiddle Demo
Just in case someone else comes along with the same question:
Instead of trying to use some amazing query, I ended up creating an array of date_columns_names and a loop in the program that was calling this query, and for each date_column_name, performing teh asme query. It is a bit slower, but it does work
I am aggregating data and I cannot sum certain columns so I would like to take the most frequent observation from that column, or the mode value. Each ID can have only one site and number, so if there are ties then pick the smaller of the two numbers.
Example follows:
ID site number
1 3 45
1 3 45
1 2 56
1 3 56
2 4 5
2 5 5
2 5 3
2 5 5
I want it to look like:
ID site number
1 3 45
2 5 5
Here's one way of doing it:
with aggregation as
(
select id
, site
, number
, numberCount = count(1)
from SiteNumbers
group by id
, site
, number
), aggregateRanks as
(
select *
, idRank = row_number() over (partition by id order by numberCount desc, number, site)
from aggregation
)
select id
, site
, number
from aggregateRanks
where idRank = 1
SQL Fiddle with demo.
It matches your results, but depending on all your different cases might need some tweaking; hopefully it gives you some ideas.