-- write a SQL query to find the players among the 10 least expensive players per hit and among the 10 least expensive players per RBI in 2001.
--     Your query should return a table with two columns, one for the players’ first names and one of their last names.
--     You can calculate a player’s salary per RBI by dividing their 2001 salary by their number of RBIs in 2001.
--     You may assume, for simplicity, that a player will only have one salary and one performance in 2001.
--     Order your results by player ID, least to greatest (or alphabetically by last name, as both are the same in this case!).
--     Keep in mind the lessons you’ve learned in 10.sql and 11.sql!
WITH least_expensive_per_hit AS (
    SELECT
        p."id",
        p."first_name",
        p."last_name"
    FROM "players" AS p
    JOIN "salaries" AS s
        ON s."player_id" = p."id"
    JOIN "performances" AS perf
        ON perf."player_id" = p."id"
       AND perf."year" = s."year"
    WHERE s."year" = 2001
      AND perf."H" > 0
    ORDER BY
        (s."salary" / perf."H") ASC,
        p."first_name" ASC,
        p."last_name" ASC
    LIMIT 10
),
least_expensive_per_rbi AS (
    SELECT
        p."id",
        p."first_name",
        p."last_name"
    FROM "players" AS p
    JOIN "salaries" AS s
        ON s."player_id" = p."id"
    JOIN "performances" AS perf
        ON perf."player_id" = p."id"
       AND perf."year" = s."year"
    WHERE s."year" = 2001
      AND perf."RBI" > 0
    ORDER BY
        (s."salary" / perf."RBI") ASC,
        p."first_name" ASC,
        p."last_name" ASC
    LIMIT 10
)
SELECT
    h."first_name",
    h."last_name"
FROM least_expensive_per_hit AS h
JOIN least_expensive_per_rbi AS r
    ON h."id" = r."id"
ORDER BY h."id" ASC;