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How do you handle NULL values in a SQL query to avoid incorrect results?

SQLmedium0.3 min readPremium
Frequency
Low
Asked at 1 company
Category
487
questions in SQL
Difficulty Split
130E|271M|86H
in this category
Total Bank
1,863
across 7 categories
Asked at these companies
Swiggy
Key Concepts Tested
joinsql
Expert AnswerPremium
56 wordsInterview-ready
**Default**: COALESCE(col, 0). **Equality**: col IS NULL; (col = val OR (col IS NULL AND val IS NULL)) for null-safe. **Aggregates**: COUNT(col) excludes NULL; AVG ignores NULL. **NOT IN**: Subquery with NULL returns nothing—use NOT EXISTS. **JOIN**: NULL = NULL is unknown; use COALESCE on keys or filter nulls....
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