daviddoji-cs50/problems/2024/sql/moneyball@20260428T141659.427507459Z

1.sql

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+-- write a SQL query to find the average player salary by year.
+--     Sort by year in descending order.
+--     Round the salary to two decimal places and call the column “average salary”.
+--     Your query should return a table with two columns, one for year and one for average salary.
+SELECT "year", ROUND(AVG("salary"), 2) AS "average salary"
+FROM "salaries"
+GROUP BY "year"
+ORDER BY "year" DESC;

2.sql

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+-- write a SQL query to find Cal Ripken Jr.’s salary history.
+--     Sort by year in descending order.
+--     Your query should return a table with two columns, one for year and one for salary.
+SELECT s."year", s."salary"
+FROM "salaries" AS s
+JOIN "players" AS p
+    ON s."player_id" = p."id"
+WHERE p."first_name" = "Cal" AND p."last_name" LIKE "Ripken%"
+ORDER BY "year" DESC;

3.sql

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+-- write a SQL query to find Ken Griffey Jr.’s home run history.
+--     Sort by year in descending order.
+--     Note that there may be two players with the name “Ken Griffey.” This Ken Griffey was born in 1969.
+--     Your query should return a table with two columns, one for year and one for home runs.
+SELECT perf."year", perf."hr"
+FROM "performances" AS perf
+JOIN "players" AS p
+    ON perf."player_id" = p."id"
+WHERE
+    p."first_name" = "Ken"
+    AND
+    p."last_name" LIKE "Griffey%"
+    AND
+    p."birth_year" = "1969"
+ORDER BY "year" DESC;

4.sql

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+-- write a SQL query to find the 50 players paid the least in 2001.
+--     Sort players by salary, lowest to highest.
+--     If two players have the same salary, sort alphabetically by first name and then by last name.
+--     If two players have the same first and last name, sort by player ID.
+--     Your query should return three columns, one for players’ first names, one for their last names, and one for their salaries.
+SELECT
+    p."first_name", p."last_name", s."salary"
+FROM "players" AS p
+JOIN "salaries" AS s
+    ON s."player_id" = p."id"
+WHERE s."year" = "2001"
+ORDER BY s."salary" ASC, p."first_name" ASC, p."last_name" ASC, p."id" ASC
+LIMIT 50;

5.sql

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+-- write a SQL query to find all teams that Satchel Paige played for.
+--     Your query should return a table with a single column, one for the name of the teams.
+SELECT DISTINCT t."name"
+FROM "teams" AS t
+JOIN "performances" AS perf
+    ON perf."team_id" = t."id"
+JOIN "players" AS p
+    ON p."id" = perf."player_id"
+WHERE p."first_name" = "Satchel" AND p."last_name" = "Paige";

6.sql

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+-- write a SQL query to return the top 5 teams, sorted by the total number of hits by players in 2001.
+--     Call the column representing total hits by players in 2001 “total hits”.
+--     Sort by total hits, highest to lowest.
+--     Your query should return two columns, one for the teams’ names and one for their total hits in 2001.
+SELECT
+    t."name",
+    SUM(perf."H") AS "total hits"
+FROM "teams" AS t
+JOIN "performances" AS perf
+    ON perf."team_id" = t."id"
+WHERE perf."year" = '2001'
+GROUP BY t."id", t."name"
+ORDER BY "total hits" DESC
+LIMIT 5;

7.sql

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+-- write a SQL query to find the name of the player who’s been paid the highest salary, of all time, in Major League Baseball.
+--     Your query should return a table with two columns, one for the player’s first name and one for their last name.
+SELECT p."first_name", p."last_name"
+FROM "players" AS p
+JOIN "salaries" AS s
+    ON s."player_id" = p."id"
+ORDER BY s."salary" DESC
+LIMIT 1;

8.sql

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+-- write a SQL query to find the 2001 salary of the player who hit the most home runs in 2001.
+--     Your query should return a table with one column, the salary of the player.
+SELECT s."salary"
+FROM "salaries" AS s
+JOIN "performances" AS perf
+    ON perf."player_id" = s."player_id"
+WHERE s."year" = '2001' AND perf."year" = '2001'
+ORDER BY perf."HR" DESC
+LIMIT 1;

9.sql

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+-- write a SQL query to find the 5 lowest paying teams (by average salary) in 2001.
+--     Round the average salary column to two decimal places and call it “average salary”.
+--     Sort the teams by average salary, least to greatest.
+--     Your query should return a table with two columns, one for the teams’ names and one for their average salary.
+SELECT
+    t."name",
+    ROUND(AVG(s."salary"), 2) AS "average salary"
+FROM "teams" AS t
+JOIN "salaries" AS s
+    ON s."team_id" = t."id"
+WHERE s."year" = '2001'
+GROUP BY t."id", t."name"
+ORDER BY "average salary" ASC
+LIMIT 5;