[Solved] What does the SQL function COALESCE do? — Ans: Returns the first non-NULL value from its arguments | SQL

SQL - CASE Expressions

What does the SQL function COALESCE do?

AReturns the first non-NULL value from its arguments

BReturns NULL if two values are equal

CAlways returns the last value in the list

DConverts NULL values to zero

Step-by-Step Solution

Solution:

Step 1: Understand COALESCE behavior
COALESCE checks each argument in order and returns the first one that is not NULL.
Step 2: Compare with other options
NULLIF returns NULL if two values are equal, which is different. COALESCE does not convert NULL to zero automatically.
Final Answer:
Returns the first non-NULL value from its arguments -> Option A
Quick Check:
COALESCE = first non-NULL [OK]

Quick Trick: COALESCE picks first non-NULL value in order [OK]

Common Mistakes:

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What does the SQL function COALESCE do?