Solution:Step 1: Understand the requirementWe want orders in 2023 that do NOT appear in 2024.Step 2: Choose correct set operationEXCEPT returns rows in first query not in second, so orders_2023 EXCEPT orders_2024 fits.Step 3: Check other optionsSELECT order_id, customer_id FROM orders_2024 EXCEPT SE

[Solved] You have two tables:orders_2023 and orders_2024, both with columns order_id and customer_id.You want to find all orders from 2023 that were NOT repeated in 2024.... | SQL

SQL - Set Operations

You have two tables:
orders_2023 and orders_2024, both with columns order_id and customer_id.

You want to find all orders from 2023 that were NOT repeated in 2024.

Which query correctly finds these unique 2023 orders?

ASELECT order_id, customer_id FROM orders_2023 INTERSECT SELECT order_id, customer_id FROM orders_2024;

BSELECT order_id, customer_id FROM orders_2024 EXCEPT SELECT order_id, customer_id FROM orders_2023;

CSELECT order_id, customer_id FROM orders_2023 UNION SELECT order_id, customer_id FROM orders_2024;

DSELECT order_id, customer_id FROM orders_2023 EXCEPT SELECT order_id, customer_id FROM orders_2024;

Step-by-Step Solution

Solution:

Step 1: Understand the requirement
We want orders in 2023 that do NOT appear in 2024.
Step 2: Choose correct set operation
EXCEPT returns rows in first query not in second, so orders_2023 EXCEPT orders_2024 fits.
Step 3: Check other options
SELECT order_id, customer_id FROM orders_2024 EXCEPT SELECT order_id, customer_id FROM orders_2023; reverses order, giving 2024 unique orders. SELECT order_id, customer_id FROM orders_2023 INTERSECT SELECT order_id, customer_id FROM orders_2024; returns common orders. SELECT order_id, customer_id FROM orders_2023 UNION SELECT order_id, customer_id FROM orders_2024; combines all orders.
Final Answer:
SELECT order_id, customer_id FROM orders_2023 EXCEPT SELECT order_id, customer_id FROM orders_2024; -> Option D
Quick Check:
2023 orders minus 2024 orders = unique 2023 orders [OK]

Quick Trick: Use EXCEPT with 2023 first, 2024 second to find unique 2023 orders [OK]

Common Mistakes:

MISTAKES

Swapping table order in EXCEPT
Using INTERSECT instead of EXCEPT
Using UNION which combines all rows

Master "Set Operations" in SQL

9 interactive learning modes - each teaches the same concept differently

Learn Why Deep Visual Try Challenge Project Recall Time

More SQL Quizzes

You have two tables:

Step 1: Understand the requirement

Step 2: Choose correct set operation

Step 3: Check other options

Final Answer:

Quick Check:

Want More Practice?