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SQL CASE WHEN Interview Questions
CASE WHEN questions test how you express conditional logic in SQL.
Expect bucketing, conditional aggregation, and custom labels based on multiple conditions.
Interviewers look for correct ordering of conditions and clear reasoning.
42Questions
22Companies
Common SQL CASE WHEN interview patterns
- Bucketing continuous values into ranges
- Conditional counts and sums
- Custom labels based on multiple conditions
- Handling NULLs in CASE logic
- Conditional joins and filters
SQL CASE WHEN interview questions
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Common mistakes with SQL CASE WHEN
- Missing ELSE clauses for unmatched cases
- Overlapping or incorrect condition order
- Not handling NULLs explicitly
- Using CASE when a JOIN or lookup table is clearer
- Mixing data types in CASE outputs
How CASE WHEN questions are evaluated in interviews
Correct logic and ordering are more important than syntax tricks.
Explain your assumptions and how edge cases are handled.
Keep CASE statements readable and well-structured.