MySQL Solution
Code\n\n# Write your MySQL query statement below\nselect Employees.employee_id from Employees natural left join Salaries \nwhere Salaries.salary is null\nunion 
# Code\n```\n# Write your MySQL query statement below\nselect Employees.employee_id from Employees natural left join Salaries \nwhere Salaries.salary is null\nunion \nselect Salaries.employee_id from salaries natural left join Employees \nwhere Employees.name is null\norder by employee_id;\n```
['MySQL']