[Solved] What will be the result of this query?SELECT * FROM products LEFT JOIN sales ON products.id = sales.product_id WHERE sales.sale_date IS NULL; | PostgreSQL

PostgreSQL - Joins in PostgreSQL

What will be the result of this query?

SELECT * FROM products LEFT JOIN sales ON products.id = sales.product_id WHERE sales.sale_date IS NULL;

AAll products with their sales records

BSyntax error due to WHERE clause

COnly sales records without matching products

DProducts that have no sales records

Step-by-Step Solution

Solution:

Step 1: Understand LEFT JOIN with WHERE condition
LEFT JOIN returns all products and matching sales; WHERE filters rows where sales.sale_date is NULL.
Step 2: Interpret NULL in sales.sale_date
NULL means no matching sales record exists for those products.
Final Answer:
Products that have no sales records -> Option D
Quick Check:
LEFT JOIN + IS NULL filters unmatched left rows [OK]

Quick Trick: Use LEFT JOIN with IS NULL to find unmatched rows [OK]

Common Mistakes:

Master "Joins in PostgreSQL" in PostgreSQL

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What will be the result of this query?