SQL
Find Records Unique to One Table Using EXCEPT
Identify and retrieve rows that exist in one table but not in another, effectively finding differences using the SQL EXCEPT set operator.
SELECT product_id, product_name, price
FROM current_products
EXCEPT
SELECT product_id, product_name, price
FROM historical_products;
How it works: The `EXCEPT` (or `MINUS` in Oracle) set operator returns all distinct rows that are returned by the first `SELECT` statement and not returned by the second `SELECT` statement. This is highly useful for comparing two tables or result sets to find discrepancies, such as products in a 'current' list that are not in a 'historical' archive.