Comparing rows of the same table with multiple conditions - sql

Question

Here is a table
ID | Player | Position | Points
1 | Ryan | QB | 75
2 | Matt | RB | 80
3 | Mike | WR | 66
4 | Jay | QB | 71
6 | Alvin | TE | 73
7 | Adrian | TE | 84
8 | Hill | WR | 71
9 | Charles| RB | 53
10 | Bell | WR | 87
11 | Rob | TE | 49
12 | Alex | RB | 92
13 | Drew | QB | 84
14 | Mack | TE | 59
15 | Nick | WR | 33
I want to report all the players in the position of the player having highest points and top 2 players of the other positions. In this example, "Alex" has the highest points and is a "RB". So I want to report all players from "RB" and top 2 from "QB", "TE", "WR" and order by points with in each group. I'm using sqlite3. I can do this programmatically using python and sqlite3 but i was wondering if this could be done only using sql
ID | Player | Position | Points
12 | Alex | RB | 92
2 | Matt | RB | 80
9 | Charles| RB | 53
13 | Drew | QB | 84
1 | Ryan | QB | 75
10 | Bell | WR | 87
8 | Hill | WR | 71
7 | Adrian | TE | 84
6 | Alvin | TE | 73
Thanks for your help

Answer 1

This is tricky in "traditional" SQLite. I would recommend union all:
with top1 as (
select t.*
from t
order by points desc
limit 1
)
select t.*
from t
where t.position = (select t1.position from top1 t1)
union all
select t.*
from t
where t.position <> (select t1.position from top1 t1) and
(select count(*)
from t t2
where t2.position = t.position and
t2.points >= t.points
) <= 2;
This assumes that the points values are unique. Ties are much harder to deal with in SQLite.
I might recommend that you consider upgrading to SQLite version 3.25.0 or use another database. Such a query would be much simpler using ISO/ANSI standard window functions.
With window functions, it would look like:
select t.*
from (select t.*,
row_number() over (partition by position order by points desc) as seqnum,
first_value(position) over (order by points desc) as first_position
from t
) t
where seqnum <= 2 or position = first_position