Question Description
Im trying to learn for my Computer Science class and Im stuck. Can you help?
Exercise 7-2
In this project, you will write SQL statements that return team
names, games played, and number of at-bats from the teamstats
table in the baseball_stats database. You will also write SQL state-
ments that return the teams that have the least and most all-time
home runs. For these select queries, you will need to use the LIMIT
keyword, which restricts the number of records returned from the
database. For example, if you specify a value of 10 with the LIMIT
keyword, the database returns the ?rst 10 records that match the con-
ditions of your query. Finally, you will write SQL statements that use
the SUM() function to return the total number of games played by all
teams and the AVG() function to return the common batting average
for all teams.
1. Return to MySQL Monitor.
2. Enter the following SELECT statement, which returns the team,
G (games played), and AB (at bats) ?elds from the teamstats
table:
mysql> SELECT team, G, AB FROM teamstats;[ENTER ]
3. Enter the following SELECT statement, which returns the team,
G (games played), and AB (at bats) ?elds from the teamstats
table, sorted by team name:
mysql> SELECT team, G, AB FROM teamstats ORDER BY
team;[ENTER ]
4. Enter the following SELECT statement, which returns the team,
G (games played), and AB (at bats) ?elds from the teamstats
table, reverse sorted by team name:
mysql> SELECT team, G, AB FROM teamstats ORDER BY
team DESC;[ENTER ]
5. Enter the following SELECT statement, which returns the team
and HR (home runs) ?elds. The statement sorts the records by
the HR ?eld and includes the LIMIT keyword, assigned a value
of 1. Because the records are sorted in ascending order, the
statement returns the ?rst record, which lists the team with
the least all-time home runs: the Tampa Bay Rays, with 1713.
mysql> SELECT team, HR FROM teamstats ORDER BY HR
LIMIT 1;[ENTER ]
6. Enter the following SELECT statement, which also returns
the team and HR (home runs) ?elds. The statement reverse
sorts the records by the HR ?eld and includes the LIMIT key-
word, assigned a value of 1. Because the records are sorted
in descending order, the statement returns the ?rst record,
which lists the team with the most all-time home runs: the
New York Yankees, with 13,914.
mysql> SELECT team, HR FROM teamstats ORDER BY HR
DESC LIMIT 1;[ENTER ]
7. Enter the following SELECT statement, which uses the SUM()
function to return the total number of games played by sum-
ming the contents of the G ?elds. Because each game played
was between two teams in the database, the sum will be twice
the actual number of games, so you divide the result by two.
You should see a value of 182,525.
mysql> SELECT SUM(G)/2 FROM teamstats;[ENTER ]
8. Enter the following SELECT statement, which uses the AVG()
function to return the batting average for all teams by averag-
ing the contents of the AVG ?elds. You should see a value of
0.26199999650319.
mysql> SELECT AVG(AVG) FROM teamstats;[ENTER ]
9. Unfortunately, this is not the true all-time batting average, 441
because each team has a di?erent number of at-bats. Enter
the following SELECT statement, which gets the weighted
average per team, and divides by the total number of at-bats.
You should see a value of 0.26256022536176.
mysql> SELECT SUM(AVG*AB)/SUM(AB) FROM
teamstats;[ENTER ]
