I am stuck in a query. i have two tables player and player_attributes with player_api_id as primary key.
I need to find the youngest,oldest player and the average overall rating of the oldest and youngest player.
Query to write the youngest and oldest player:
select player_name, birthday,YEAR(CURDATE()) - YEAR(birthday) as age from player where
birthday=(select max(birthday) from player)
or
birthday=(select min(birthday) from player)
Query for the average overall rating of all players:
SELECT player_api_id, avg(overall_rating) as avg_score,
FROM (
SELECT player_api_id, overall_rating FROM player_attributes
) as p
GROUP BY player_api_id;
Error while joining:
select player_api_id, avg(overall_rating),min(birthday),max(birthday) as avg_score
FROM (
SELECT player_api_id, overall_rating FROM player_attributes
) as p
join
(select birthday from player) as p1
on p.player_api_id=p1.player_api_id
GROUP BY player_api_id;
I am confused now??
There is no reason to use subqueries just to select columns. In fact, in MySQL, it is a really, really bad idea -- because MySQL materializes the subqueries.
So, just do:
select pa.player_api_id, avg(overall_rating) as avg_score,
min(p.birthday), max(p.birthday)
from player_attributes pa join
player p
on pa.player_api_id = p.player_api_id
group by pa.player_api_id;
I'm not sure if the rest of the logic is okay. But this should at least fix the syntax error.
Related
I have a table that roughly looks like the following:
winner_name
loser_name
Person A
Person B
Person A
Person C
Person B
Person A
Person C
Person B
I'm trying to return a table that looks like the following:
player_name
number_wins
number_losses
Person A
2
1
Person B
1
2
Person C
1
1
I can't quite figure out how to get there. I have been able to write a query that returns player_name and either number_wins or number_losses, but not both.
SELECT winner_name AS player_name, COUNT(*) AS number_wins
FROM my_table
GROUP BY player_name
I have looked into using procedures, functions, and subqueries to do this but I haven't found the right solution yet. Any direction would be helpful.
You need to pivot the names into the same column using UNION. Then you can calculate the sum of wins and losses.
SELECT player_name, SUM(win) AS number_wins, SUM(loss) AS number_losses)
FROM (
SELECT winner_name AS player_name, 1 AS win, 0 AS loss
FROM my_table
UNION ALL
SELECT loser_name AS player_name, 0 AS win, 1 AS loss
FROM my_table
) AS x
GROUP BY player_name
Since each aggregate statistic is for a different group (one for winner_name, the other for loser_name), they can't be calculated in the same query, but each query can be run separately and then combined with a JOIN. Simply take each query:
SELECT winner_name AS player, COUNT(loser_name) AS wins
FROM games
GROUP BY winner_name
;
SELECT loser_name AS player, COUNT(winner) AS losses
FROM games
GROUP BY loser_name
;
and join on the common attribute, the player name:
SELECT gw.player, gw.wins, gl.losses
FROM (
SELECT winner_name AS player, COUNT(loser_name) AS wins
FROM games
GROUP BY winner_name
) AS gw
JOIN (
SELECT loser_name AS player, COUNT(winner_name) AS losses
FROM games
GROUP BY loser_name
) AS gl
ON gl.player = gw.player
;
Whether using unions or joins, each distinct group that is the basis for aggregate statistics will require a separate sub-select.
I have this schema:
CLUB(Name, Address, City)
TEAM(TeamName, club)
PLAYER(Badge, teamName)
MATCH(matchNumber, player1, player2, club, winner)
I need to make this query:
For each club, find the number of players in that club that have won
at least two games.
I wrote this:
SELECT teamName
From TEAM t join Match m1 on t.club=m1.club
WHERE Q2 >= ALL Q1
Q1:
SELECT Count (Distinct winner)
FROM MATCH
WHERE match m join player p on m. winner=player.badge
GROUP BY teamName
Q2:
SELECT Count (distinct winner)
FROM match m2
WHERE m2.club=m1.club
I don’t know if it is correct, however I heard that using this form where I confront two counts is not the best. Why?
Try something like this:
SELECT club, COUNT(*) as PlayerCount
FROM (SELECT club, winner
FROM match
GROUP BY club, winner
HAVING COUNT(*) > 1) a
GROUP BY club
The inner query should limit results to club/player combinations that have 2 or more wins, and the outer query will count the number of these players per club.
I don’t know if it is correct, however I heard that using this form where I confront two counts is not the best. Why?
Comparing two count subqueries is fine if you need to, but a good rule of thumb is to hit each table as few times as possible. Using multiple subqueries will end up hitting each table multiple times, and will usually result in longer execution times.
Try this query
SELECT t.club, COUNT(*)
FROM TEAM t
JOIN PLAYER p ON p.teamName = t.TeamName
JOIN (
-- Won at least 2 matches.
SELECT club, winner, COUNT(*) AS TheCount
FROM MATCH
GROUP BY club, winner
HAVING COUNT(*) > 1
) w ON w.winner = p.badge AND w.club = t.club
GROUP BY t.club
I'm looking for help using sum() in my SQL query:
Task: Count tournament wins of all players. (one number per player) (battles.result = 1 means Player1 wins)
SELECT members.id, members.name,
(
SELECT SUM(battles.result = 1)
FROM battles
WHERE members.id = battles.player1 AND battles.result=1 order by battles.gametime
( as wins,
FROM members
Next: Only count ONE result per two players.
So if there are multiple results of two players, count only the first result (first gametime).
I've already tried using order by battles.player2, but i guess there is a much better solution?
You can easily get the result by doing a join and aggregation instead. Try:
SELECT A.id, A.name, SUM(IFNULL(B.result,0)) wons
FROM members A LEFT JOIN battles B
ON A.id=B.player1
GROUP BY A.id, A.name;
EDIT: This has been solved, requiring a subquery into the appearances table. Here is the working solution.
SELECT concat(m.nameFirst, ' ', m.nameLast) as Name,
m.playerID as playerID,
sum(b.HR) as HR
FROM Master AS m
INNER JOIN Batting AS b
ON m.playerID=b.playerID
WHERE ((m.weight/(m.height*m.height))*703) >= 27.99
AND m.playerID in (SELECT playerID FROM appearances GROUP BY playerID HAVING SUM(G_1b+G_dh)/SUM(G_All) >= .667)
GROUP BY playerID, Name
HAVING HR >= 100
ORDER BY HR desc;
I'm working with the Lahman baseball stat database, if anyone's familiar.
I'm trying to retrieve a list of all large, slugging first basemen, and the data I need is spread across three different tables. The way I'm doing this is finding players of a minimum BMI, who have spent at least 2/3 of their time at first/designated hitter, and have a minimum number of home runs.
'Master' houses player names, height, weight (for BMIs).
'Batting' houses HR.
'Appearances' houses games played at first, games played at DH, and total games.
All three databases are connected by the same 'playerID' value.
Here is my current query:
SELECT concat(m.nameFirst, ' ', m.nameLast) as Name,
m.playerID as playerID,
sum(b.HR) as HR
FROM Master AS m
INNER JOIN Batting AS b
ON m.playerID=b.playerID
INNER JOIN Appearances AS a
ON m.playerID=a.playerID
GROUP BY Name, playerID
HAVING ((m.weight/(m.height*m.height))*703) >= 27.99
AND ((SUM(IFNULL(a.G_1b,0)+IFNULL(a.G_dh,0)))/SUM(IFNULL(a.G_All,0))) >= .667
AND HR >= 200
ORDER BY HR desc;
This appears correct to me, but when entered it never returns (runs forever) - for some reason I think it has something to do with the inner join of the appearances table. I also feel like there's a problem with combining m.weight/m.height in a "HAVING" clause, but with aggregates involved I can't use "WHERE." What should I do?
Thanks for any help!
EDIT: After removing all conditionals, I'm still getting the same (endless) result. This is my simpler query:
SELECT concat(m.nameFirst, ' ', m.nameLast) as Name,
m.playerID as playerID,
sum(b.HR) as HR
FROM Master AS m
INNER JOIN Batting AS b
ON m.playerID=b.playerID
INNER JOIN Appearances AS a
ON m.playerID=a.playerID
GROUP BY playerID, Name
ORDER BY HR desc;
My guess is that the problem with your query is that each player has appeared many times (appearances) and at bat many times. Say a player has been at bat 1000 times in 100 games. Then the join -- as you have written it -- will have 100,000 rows just for that player.
This is just a guess because you have provided no sample data to verify if this is the problem.
The solution is to pre-aggregate the appearances and games tables as subqueries (at the playerId level) and then join them back.
I am quite new on SQL and I am trying to practice to improve myself.
I have a database which has a
Table : Players, Teams, Plays, and Wins
Players : pid, pname, age, country
Plays : pid, season, tid, value ( pid -> pid in Players, tid -> tid in Teams )
Teams : tid, tname, tcolor, tbudget
Wins : wtid, ltid, season, wscore, lscore ( wtid,ltid -> tid in Teams )
The question is Find the name of the players whose played in atleast 2 dif. teams with same color
What I did is
SELECT DISTINCT P.pname
FROM Players P
,Teams T1
GROUP BY T1.tcolor
HAVING 1 < (
SELECT COUNT (10)
FROM Teams T2
WHERE T1.tcolor=T2.tcolor)
When I try to query this , I get an error which is ;
Error Code: 1630
FUNCTION PRALATEST.COUNT does not exist. Check the 'Function Name Parsing and Resolution' section in the Reference Manual
In which part am I doing wrong?
Try this:
select pname
from Players
join Plays on Plays.pid = Players.pid
join Teams on Teams.tid = Plays.tid
group by pname, tcolor
having count(Teams.tname) > 1
The condition count(Teams.tname) > 1 is in a having clause instead of a where clause becuase it needs to operate on the results AFTER the group by is performed.
Couple things. Your error message is because you put a numeric constant in the COUNT function. You should just use an asterisk.
Also, you have not specified a join condition for your Players and Teams tables. As a result, you are doing a product join (probably not what you want). I'm guessing you need to join to your Plays table.
You should change your coding practice to use "explicit" join syntax to avoid errors like this in the future.