To answer this question, we need to understand what a self-join is.
A self-join occurs when we join a table to itself. In other words, we treat the table as two separate entities and join them based on a common column or condition.
Let's go through each option to understand why it is correct or incorrect:
Option A) We are joining more than 2 tables - This option is incorrect. Joining more than 2 tables is not a defining characteristic of a self-join.
Option B) We are joining a table to itself - This option is correct. A self-join occurs when we join a table to itself, treating it as two separate entities.
Option C) We are using left and right join together - This option is incorrect. Using left and right joins together is not a defining characteristic of a self-join.
Option D) None of the above - This option is the correct answer. The correct definition of a self-join is given in option B, and none of the other options accurately describe a self-join.
The correct answer is D) None of the above. This option is correct because a self-join occurs when we join a table to itself.