250+ TOP MCQs on Join Operations and Answers

Database Multiple Choice Questions on “Join Operations”.

1. A_____ is a query that retrieves rows from more than one table or view:
a) Start
b) End
c) Join
d) All of the mentioned

Answer: c
Clarification: An SQL join clause combines records from two or more tables in a database. It creates a set that can be saved as a table or used as it is. A JOIN is a means for combining fields from two tables by using values common to each.

2. A condition is referred to as __________
a) Join in SQL
b) Join condition
c) Join in SQL & Condition
d) None of the mentioned

Answer: b
Clarification: An SQL join clause combines records from two or more tables in a database. It creates a set that can be saved as a table or used as it is. A JOIN is a means for combining fields from two tables by using values common to each.

3. Which oracle is the join condition is specified using the WHERE clause:
a) Oracle 9i
b) Oracle 8i
c) Pre-oracle 9i
d) Pre-oracle 8i

Answer: c
Clarification: Oracle 9i is a version of the Oracle Database. The i stands for “Internet” to indicate that 9i is “Internet ready”.

4. How many join types in join condition:
a) 2
b) 3
c) 4
d) 5

Answer: d
Clarification: INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN, EQUIJOIN.

5. Which are the join types in join condition:
a) Cross join
b) Natural join
c) Join with USING clause
d) All of the mentioned

Answer: d
Clarification: INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN, EQUIJOIN are the types of joins.

6. Which product is returned in a join query have no join condition:
a) Equijoins
b) Cartesian
c) Both Equijoins and Cartesian
d) None of the mentioned

Answer: b
Clarification: A Cartesian coordinate system is a coordinate system that specifies each point uniquely in a plane by a pair of numerical coordinates.

7. Which is a join condition contains an equality operator:
a) Equijoins
b) Cartesian
c) Both Equijoins and Cartesian
d) None of the mentioned

Answer: a
Clarification: An equi-join is a specific type of comparator-based join, that uses only equality comparisons in the join-predicate.

8. Which join refers to join records from the write table that have no matching key in the left table are include in the result set:
a) Left outer join
b) Right outer join
c) Full outer join
d) Half outer join

Answer: b
Clarification: A right outer join will return all the rows that an inner join returns plus one row for each of the other rows in the second table that did not have a match in the first table. It is the same as a left outer join with the tables specified in the opposite order.

9. Which operation are allowed in a join view:
a) UPDATE
b) INSERT
c) DELETE
d) All of the mentioned

Answer: d
Clarification: The DELETE statement is used to delete rows in a table. The UPDATE statement is used to update existing records in a table. The INSERT INTO statement is used to insert new records in a table.

10. Which view that contains more than one table in the top-level FROM clause of the SELECT statement:
a) Join view
b) Datable join view
c) Updatable join view
d) All of the mentioned

Answer: c
Clarification: The DELETE statement is used to delete rows in a table. The UPDATE statement is used to update existing records in a table. The INSERT INTO statement is used to insert new records in a table.