RANK
RANK
The RANK() function assigns a unique rank to each value within an ordered group of values.
The rank value starts at 1 and continues up sequentially. If two values are the same, they have the same rank.
Syntax
RANK() OVER (
  [ PARTITION BY <expr1> ]
  ORDER BY <expr2> [ { ASC | DESC } ]
  [ <window_frame> ]
)
Examples
Create the table
CREATE TABLE employees (
  employee_id INT,
  first_name VARCHAR,
  last_name VARCHAR,
  department VARCHAR,
  salary INT
);
Insert data
INSERT INTO employees (employee_id, first_name, last_name, department, salary) VALUES
  (1, 'John', 'Doe', 'IT', 90000),
  (2, 'Jane', 'Smith', 'HR', 85000),
  (3, 'Mike', 'Johnson', 'IT', 82000),
  (4, 'Sara', 'Williams', 'Sales', 77000),
  (5, 'Tom', 'Brown', 'HR', 75000);
Ranking employees by salary
SELECT
  employee_id,
  first_name,
  last_name,
  department,
  salary,
  RANK() OVER (ORDER BY salary DESC) AS rank
FROM
  employees;
Result:
| employee_id | first_name | last_name | department | salary | rank | 
|---|---|---|---|---|---|
| 1 | John | Doe | IT | 90000 | 1 | 
| 2 | Jane | Smith | HR | 85000 | 2 | 
| 3 | Mike | Johnson | IT | 82000 | 3 | 
| 4 | Sara | Williams | Sales | 77000 | 4 | 
| 5 | Tom | Brown | HR | 75000 | 5 |