Delete Group of Records based on Group Statistic - sql

Question

I have the following two example tables
Teams
Team ID
Team Name
1
Bears
2
Tigers
3
Lions
4
Sharks
Players
Player ID
Name
Team ID
Playtime
1
John
1
5
2
Adam
1
4
3
Smith
1
5
4
Michelle
2
5
5
Stephanie
2
10
6
David
2
10
7
Courtney
2
2
8
Frank
2
7
9
Teresa
2
1
10
Michael
3
3
11
May
4
1
12
Daniel
4
1
13
Lisa
4
4
I need a select statement with the following criteria
Select all teams with less than 4 players
Figure out the total playtime for all players on those teams and sort the resulting table based on this in descending order
Based on the example given, I would want a table that looks like this:
Teams
Team Name
Num Players
Total Playtime
Bears
3
14
Sharks
3
6
Lions
1
3
Finally, I want to cut all even rows from the previous table, so the final table would look like:
Team Name
Num Players
Total Playtime
Bears
3
14
Lions
1
3

Answer 1

You may try the following:
Query #1
SELECT
t."Team Name",
COUNT(p."Player ID") as "Num Players",
SUM(p."Playtime") as "Total Playtime"
FROM
teams t
LEFT JOIN
players p ON t."Team ID"=p."Team ID"
GROUP BY
t."Team Name"
HAVING
COUNT(p."Player ID") < 4
ORDER BY
SUM(p."Playtime") DESC;
Team Name
Num Players
Total Playtime
Bears
3
14
Sharks
3
6
Lions
1
3
Query #2
SELECT
t1."Team Name",
t1."Num Players",
t1."Total Playtime"
FROM (
SELECT
ROW_NUMBER() OVER (ORDER BY SUM(p."Playtime") DESC) as rn,
t."Team Name",
COUNT(p."Player ID") as "Num Players",
SUM(p."Playtime") as "Total Playtime"
FROM
teams t
LEFT JOIN
players p ON t."Team ID"=p."Team ID"
GROUP BY
t."Team Name"
HAVING
COUNT(p."Player ID") < 4
) t1
WHERE MOD(rn,2)=1
ORDER BY rn;
Team Name
Num Players
Total Playtime
Bears
3
14
Lions
1
3
View on DB Fiddle
Let me know if this works for you.