CS TECHIIE

SQL Program 47: Rank employees by department salary

SQL learning illustration

CS TECHIIE | SQL Notes and Solutions

Practical SQL exercise: Uses a window function to rank within each department.

Objective

Uses a window function to rank within each department.

Explanation

Read the statement clause by clause and predict the result before executing it. These examples use common relational SQL; table setup and exact syntax can vary between MySQL, PostgreSQL, SQL Server, Oracle and SQLite.

Safety check

Before running UPDATE or DELETE, run a SELECT with the same WHERE condition. Use a test database and a transaction for changes you need to verify.

Program / SQL Solution

SELECT employee_name,department_id,salary,DENSE_RANK() OVER (PARTITION BY department_id ORDER BY salary DESC) AS salary_rank FROM employees;

Practice and revision

  • Run the example and verify the output.
  • Change the input and test normal, boundary and invalid cases.
  • Write the solution again without looking at the notes.

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