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Which situation best shows why a CASE expression is useful in SQL?

easy📝 Conceptual Q2 of 15
SQL - CASE Expressions
Which situation best shows why a CASE expression is useful in SQL?
ATo assign grades like 'Pass' or 'Fail' based on scores
BTo list all employees in alphabetical order
CTo count the total number of rows in a table
DTo remove duplicate rows from a result
Step-by-Step Solution
Solution:

  1. Step 1: Identify the need for conditional output

    Assigning grades like 'Pass' or 'Fail' depends on score values, which requires conditional logic.

  2. Step 2: Match with CASE expression use

    CASE expressions allow returning different text based on conditions, perfect for grading.

  3. Final Answer:

    To assign grades like 'Pass' or 'Fail' based on scores -> Option A

  4. Quick Check:

    CASE use case = conditional output [OK]
Quick Trick: Use CASE to convert values into categories [OK]
Common Mistakes:
  • Confusing sorting or counting with conditional logic
  • Using CASE for operations it can't do

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