In which case would you use a FULL OUTER JOIN?
A.
Both tables have NULL values.
B.
You want all unmatched data from one table.
C.
You want all matched and unmatched data from only one table.
D.
You want all unmatched data from both tables.
E.
You want all matched data from both tables.
F.
One of the tables has more data than the other.
Explanation:
Oracle9i also makes it possible for you to easily execute a full outer join, including all records from
the tables that would have been displayed if you had used both LEFT OUTER JOIN or RIGTH
OUTER JOIN clauses.
Incorrect Answers:
A: You will not use a FULL OUTER JOIN if both tables have NULL values.
B: You will not use a FULL OUTER JOIN if you want all unmatched data from one table. Only
LEFT OUTER JOIN or RIGTH OUTER JOIN needs to be used.
C: You want all unmatched, not matched, data from both tables.
E: It is not a criterion to use a FULL OUTER JOIN if one of the tables has more data than the
other.
F: You want all unmatched, not matched data or a combination of matched and unmatched data,
from both tables, not one table.OCP Introduction to Oracle 9i: SQL Exam Guide, Jason
Couchman, p. 109-118Chapter 3: Advanced Data Selection in Oracle