[Solved] Which of the following is TRUE about aliasing a subquery in the FROM clause? — Ans: Alias is mandatory to reference the subquery result | PostgreSQL

PostgreSQL - Subqueries in PostgreSQL

Which of the following is TRUE about aliasing a subquery in the FROM clause?

AAlias is mandatory to reference the subquery result

BAlias can only be a number

CAlias must be the same as the original table name

DAlias is optional and can be omitted

Step-by-Step Solution

Solution:

Step 1: Check alias requirement for subqueries in FROM
PostgreSQL requires an alias for subqueries in the FROM clause to reference their columns.
Step 2: Understand alias rules
The alias can be any valid identifier but is mandatory to avoid syntax errors.
Final Answer:
Alias is mandatory to reference the subquery result -> Option A
Quick Check:
Subquery alias = Mandatory [OK]

Quick Trick: Always give an alias to subqueries in FROM clause [OK]

Common Mistakes:

Master "Subqueries in PostgreSQL" in PostgreSQL

9 interactive learning modes - each teaches the same concept differently

Which of the following is TRUE about aliasing a subquery in the FROM clause?