SQL NOT EQUAL Operator (!=)

SQL NOT EQUAL Operator

The SQL NOT EQUAL operator is used to filter records that do not match a specified value. In SQL, the != or <> operators can be used interchangeably to represent “not equal to”. This operator is commonly used in the WHERE clause to exclude specific values from query results.

In this tutorial, we will explore the NOT EQUAL operator in SQL with syntax explanations and practical examples.

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Syntax of SQL NOT EQUAL != Operator

The basic syntax for using the NOT EQUAL operator in a WHERE clause is as follows:

SELECT column1, column2, ...
FROM table_name
WHERE column_name != value;

Alternatively, you can use the <> operator:

SELECT column1, column2, ...
FROM table_name
WHERE column_name <> value;

Explanation:

• SELECT: Specifies the columns to retrieve from the table.
• FROM: Specifies the table from which data is selected.
• WHERE: Filters records based on conditions.
• != or <>: Ensures that the values in the column are not equal to the specified value.

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Step-by-Step Examples Using SQL NOT EQUAL != Operator

1 Filtering Employees Who Are Not from a Specific Department

Let’s create an employees table to demonstrate the NOT EQUAL operator.

CREATE TABLE employees (
    id INT PRIMARY KEY AUTO_INCREMENT,
    name VARCHAR(50),
    department VARCHAR(50),
    salary DECIMAL(10,2)
);

Insert some sample data:

INSERT INTO employees (name, department, salary)
VALUES 
('Arjun', 'IT', 75000),
('Ram', 'HR', 60000),
('John', 'Finance', 80000),
('Priya', 'IT', 72000),
('David', 'Marketing', 65000);

Now, let’s fetch employees who are NOT in the IT department:

SELECT * FROM employees
WHERE department != 'IT';