juniorT-SQL

What is NULL in SQL Server?

Updated May 17, 2026

Short answer

NULL represents missing or unknown value.

Deep explanation

It is not zero or empty; it represents absence of value.

Real-world example

Employees without assigned manager.

Common mistakes

  • Using = NULL instead of IS NULL.

Follow-up questions

  • How to handle NULLs?
  • Is NULL equal to NULL?

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