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MediumSQL

Departments Without Employees

SQLDatabases

Write a SQL query that finds all departments that have no employees,
ordered by department name.

Tables

departments: id, name
employees: id, name, dept_id

deptname
1Engineering
2Marketing
3Legal
4Sales

Employees exist in Engineering (1), Marketing (2) and Sales (4) — but not Legal (3).

Expected output (column: department_name)

Legal

SQLite output format — rows are pipe-separated (|) with no column headers.

Example: SELECT id, name FROM users WHERE id = 1 → 1|Alice

Hint — use a LEFT JOIN and check for IS NULL on the employee side.

Sample tests

Test #1Legal (3) has no employees
Input: "CREATE TABLE departments (id INTEGER, name TEXT);\nCREATE TABLE employees (id INTEGER, name TEXT, dept_id INTEGER);\nINSERT INTO departments VALUES (1, 'Engineering'), (2, 'Marketing'), (3, 'Legal'), (4, 'Sales');\nINSERT INTO employees VALUES\n (1, 'Alice', 1), (2, 'Bob', 2), (3, 'Carol', 1), (4, 'Dave', 4);"
Output: "Legal"
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