[Solved] What is wrong with this query if we want to list all customers and their orders, including customers with no orders?SELECT c.name, o.order_id FROM Customers c INNER JOIN Orders o ON c.id = o.... | SQL

SQL - LEFT and RIGHT JOIN

What is wrong with this query if we want to list all customers and their orders, including customers with no orders?

SELECT c.name, o.order_id FROM Customers c INNER JOIN Orders o ON c.id = o.customer_id;

AINNER JOIN excludes customers without orders; should use LEFT OUTER JOIN

BThe ON clause is missing

CThe SELECT statement is missing table aliases

DOrders table should be first in the FROM clause

Step-by-Step Solution

Solution:

Step 1: Understand INNER JOIN behavior
INNER JOIN returns only rows with matching keys in both tables, so customers without orders are excluded.
Step 2: Identify correct join for including all customers
LEFT OUTER JOIN keeps all customers even if no matching orders exist, showing NULL for order columns.
Final Answer:
INNER JOIN excludes customers without orders; should use LEFT OUTER JOIN -> Option A
Quick Check:
Use LEFT OUTER JOIN to include all left table rows [OK]

Quick Trick: Use LEFT OUTER JOIN to include unmatched left table rows [OK]

Common Mistakes:

MISTAKES

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What is wrong with this query if we want to list all customers and their orders, including customers with no orders?