easyJOINsSelf JoinNULL handling

Employees Earning More Than Their Manager

Find employees whose salary is greater than their direct manager's salary.

Prompt

Employees Earning More Than Their Manager

Prompt

Given the employee table below, write a query that returns every employee whose salary is greater than their direct manager's salary.

The result should include: employee (the employee's name), employee_salary, manager (the manager's name), and manager_salary.
The employee with no manager (the CEO) can never qualify.
An employee whose manager_id points to a missing row cannot qualify either.
"Greater than" is strictly greater — equal salaries do not qualify.

Example

id	name	salary	manager_id
1	Alice	100	NULL
2	Bob	80	1
3	Carol	120	1
4	Dave	90	2

Expected result:

employee	employee_salary	manager	manager_salary
Carol	120	Alice	100
Dave	90	Bob	80

Constraints

employee.id is the primary key.
employee.manager_id is nullable and references employee.id.

Tips

An employee's manager is another row in the same table — use a self join with table aliases.
Joining on the unique primary key means no fan-out: one row per employee.

Expected concepts

Self join
Aliasing
Comparison with NULL

Schema

CREATE TABLE employee (
    id         INTEGER PRIMARY KEY,
    name       TEXT NOT NULL,
    salary     INTEGER NOT NULL,
    manager_id INTEGER REFERENCES employee(id)  -- NULL for top-level employees
);

Sample data

INSERT INTO employee (id, name, salary, manager_id) VALUES
  (1, 'Alice', 100, NULL),
  (2, 'Bob',   80,  1),
  (3, 'Carol', 120, 1),
  (4, 'Dave',  90,  2),
  (5, 'Eve',   70,  2);

Additional hidden fixtures are applied during validation to test edge cases.