SQL Operators
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 |