Beginner

174. NOT Operator

Learn how the NOT operator reverses a SQL condition.

📘 Lesson 174 of 728 ⏱ 8 min 🎯 Beginner

The NOT operator reverses the logical result of a condition. A TRUE condition becomes FALSE and a FALSE condition becomes TRUE.

NOT is useful when business requirements specify exclusions rather than direct matches.

Find employees who are not in the IT department.

SQL 
SELECT
    EmployeeName,
    Department
FROM Employees
WHERE NOT Department = 'IT';

NOT is used for exclusions, exception reports, validation rules, and filtering unwanted categories.

  • NOT reverses a condition.
  • It can be used with comparisons.
  • It can be combined with IN, LIKE, and other operators.
  • It is useful for exclusions.
  • Complex NOT conditions should be written carefully.
What does NOT do in SQL?

NOT reverses the logical result of a condition.

Why use NOT?

NOT is useful when a query needs to exclude records matching a specific condition.

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