Test: Joins Operations - Computer Science Engineering (CSE) MCQ

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.

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.

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

INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN, EQUIJOIN.

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.

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.

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

INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN, EQUIJOIN are the types of joins.

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

The answer to the above question is Option (b) Left-outer Join
A JOIN clause is used to combine rows from two or more tables, based on a related column between them.
Here are the different types of the JOINs in SQL:

• (INNER) JOIN: Returns records that have matching values in both tables
• LEFT (OUTER) JOIN: Returns all records from the left table, and the matched records from the right table
• RIGHT (OUTER) JOIN: Returns all records from the right table, and the matched records from the left table
• FULL (OUTER) JOIN: Returns all records when there is a match in either left or right table

We can see that left join keeps all the elements from the first relation irrespective of their presence in second relation.
Diagram to visualize joins: