Operating_System_Knowledge
| ID | OS_Name |
| 1 | Windows |
| 2 | Linux |
IT_Support_Technician
| ID | Name | Contact_Email | Phone_Number | Hire_Date | Operating_System_ID |
| | | | | (→ Operating_System_Knowledge.ID) |
| 1 | John Doe | john@example.com | +1 (123) 456-7890 | 2020-01-01 | 1 |
| 2 | Jane Smith | jane@example.com | +1 (123) 456-7890 | 2020-01-01 | 2 |
Network_Administrator
| ID | Name | Contact_Email | Phone_Number | Hire_Date | Operating_System_ID |
| | | | | (→ Operating_System_Knowledge.ID) |
| 1 | Mike Johnson | mike@example.com | +1 (123) 456-7890 | 2020-01-01 | 1 |
| 2 | Emily Davis | emily@example.com | +1 (123) 456-7890 | 2020-01-01 | 2 |
Employee
| ID | First_Name | Last_Name | Position | Salary | Joining_Date |
| 1 | Alice | Smith | Software Engineer | 75000 | 2019-06-01 |
| 2 | Bob | Williams | Data Analyst | 65000 | 2019-05-01 |
| 3 | Carol | Johnson | Product Manager | 85000 | 2019-07-01 |
| 4 | David | Brown | UI/UX Designer | 60000 | 2019-08-01 |
| 5 | Eve | Jones | QA Tester | 55000 | 2019-09-01 |