NOT Operator in SQL

Not in SQL-

Not operator in SQL negates whatever conditions comes after it. It is never used by itself. It is always used in conjunction with some other operators.

Syntax of Not Operator –

SELECT column1, column2
FROM table_name
WHERE NOT condition

Employee table –

Let’s say you want to find all employee that are not from department 10. To do that you have to write.

SELECT *
FROM emp
WHERE NOT DEPTNO = 10;

The Not here negates the condition that follows it. So instead of matching DEPTNO = 10, it matches anything that is Not 10.

You can also use Not operator like this. Both are equivalent.

SELECT *
FROM emp
WHERE DEPTNO <> 10;