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SQL NULL VALUES Interview Questions and tutorials

SQL NULL VALUES Interview Questions and tutorials
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SQL `NULL` represents a missing or unknown value, not zero or empty. It's used when data is unavailable or inapplicable. `NULL` can't be compared with standard operators like `=`; instead, use `IS NULL` or `IS NOT NULL`. Functions like `COALESCE()` and `IFNULL()` handle `NULL` by providing default values. In joins or conditions, misunderstanding `NULL` behavior can lead to unexpected results. Interview questions often test filtering, aggregation, and conditional logic involving `NULL`, making it essential to understand its unique behavior.

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