SQL Operators Tutorial

Example Table

We will use the following table named employees for our examples:

    CREATE TABLE employees (
        employee_id INT PRIMARY KEY,
        employee_name VARCHAR(50),
        department VARCHAR(50),
        salary DECIMAL(10, 2)
    );

    INSERT INTO employees (employee_id, employee_name, department, salary) VALUES
    (1, 'Alice Johnson', 'HR', 60000.00),
    (2, 'Bob Smith', 'IT', 75000.00),
    (3, 'Charlie Brown', 'Finance', 50000.00),
    (4, 'Diana Prince', 'IT', 80000.00),
    (5, 'Eve Davis', 'Marketing', 55000.00);
    

Employees Table

employee_id	employee_name	department	salary
1	Alice Johnson	HR	60000.00
2	Bob Smith	IT	75000.00
3	Charlie Brown	Finance	50000.00
4	Diana Prince	IT	80000.00
5	Eve Davis	Marketing	55000.00

Using SQL Operators

SQL operators are used to perform operations on data in a database. Here are some common SQL operators:

Example: Using the Equality Operator (=)

To find employees in the IT department, use the following query:

    SELECT employee_name, department
    FROM employees
    WHERE department = 'IT';
    

Result:

employee_name	Bob Smith
department	IT
employee_name	Diana Prince
department	IT

Example: Using the Greater Than Operator (>)

To find employees with a salary greater than 60000, use the following query:

    SELECT employee_name, salary
    FROM employees
    WHERE salary > 60000;
    

Result:

employee_name	Bob Smith
salary	75000.00
employee_name	Diana Prince
salary	80000.00

Example: Using the Less Than Operator (<)

To find employees with a salary less than 60000, use the following query:

    SELECT employee_name, salary
    FROM employees
    WHERE salary < 60000;
    

Result:

employee_name	Charlie Brown
salary	50000.00
employee_name	Eve Davis
salary	55000.00