Given the table orders with column discount containing values (10, NULL, 10, NULL, 15), what is the result of this query?

medium📝 query result Q13 of 15

SQL - Aggregate Functions

Given the table orders with column discount containing values (10, NULL, 10, NULL, 15), what is the result of this query?

SELECT AVG(COALESCE(discount, 0)) FROM orders;

B10

C15

DNULL

Step-by-Step Solution

Solution:

Step 1: Replace NULLs with 0 using COALESCE
Values become 10, 0, 10, 0, 15.
Step 2: Calculate average of these values
Sum = 10 + 0 + 10 + 0 + 15 = 35; Count = 5; Average = 35 / 5 = 7.
Final Answer:
7 -> Option A
Quick Check:
COALESCE replaces NULLs, AVG includes zeros [OK]

Quick Trick: Replace NULLs with zero before AVG to include them [OK]

Common Mistakes:

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