SQL Questions and Answers – SQL Self Join

This set of SQL Multiple Choice Questions & Answers (MCQs) focuses on “SQL Self Join”.

1. What is a SELF JOIN?
a) It is an irregular join
b) It is used to join a table to itself
c) It is used to join a table to other tables
d) It cannot be done in SQL
View Answer

2. Self joins are used to ________
a) Compare values in a column with other values in the same column of the same table
b) Compare values in a column with other values in the same column of the other table
c) Compare values in a column with other values in the other column of the other table
d) Compare values in a column with some given value
View Answer

3. SELF JOIN is a keyword in SQL.
a) True
b) False
View Answer

4. Which of the following is necessary for a SELF JOIN in SQL?
a) Join
b) Alias
c) Order by
d) Group by
View Answer

5. What is the syntax for self join?
a)

SELECT column_list
FROM table1 SELF JOIN table1
WHERE condition(s);

b)

SELECT column_list
FROM table1 JOIN table1
WHERE condition(s);

c)

SELECT column_list
FROM table1 T SELF JOIN table1 S
WHERE condition(s);

d)

SELECT column_list
FROM table1 T JOIN table1 S
WHERE condition(s);

SELECT column_list
FROM TABLE A (INNER | OUTER) JOIN TABLE B
WHERE condition(s);

6. To construct a SELF JOIN, how many times the same table is selected by a SELECT statement?
a) Only once
b) Twice
c) More than two times
d) Thrice
View Answer

Sanfoundry Global Education & Learning Series – SQL.

To practice all areas of SQL, here is complete set of 1000+ Multiple Choice Questions and Answers.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]