Quick Check 4.4 – Data 100, Summer 2020

JavaScript isn't enabled in your browser, so this file can't be opened. Enable and reload.

Which of the following are true regarding SQL joins? *

We have two tables "s" and "t" which have 5 records and 6 records respectively. A cross join between "s" and "t" results in a table with 11 records.

An inner join is the same as a cross join followed by some filtering.

You can implement a RIGHT OUTER JOIN using a LEFT OUTER JOIN.

An outer join between two tables "s" and "t" can result in a table that has more rows than "s."

An outer join between two tables "s" and "t" always results in a table that has more rows than "s."

Required

For the following questions consider the tables below:

What does the following query compute? *

All pairs of sailors where the first is longer than the second.

The oldest sailor.

Sailors who are younger than Popeye and Popeye.

Popeye and Sailors who are older than Popeye.

There is a serious bug in this query.

Consider the following query: SELECT r.sid, b.bid, b.bname FROM Res AS r FULL OUTER JOIN Boats AS b ON r.bid = b.bid;

How many NULL values are in the resulting r.sid column? *

How many NULL values are in the resulting b.bid column? *

Submit

Clear form

This form was created inside of UC Berkeley. Report Abuse