Do only in Oracle SQL.
Make sure to test code before submitting.
Create two tables:
Employee: empID (PK), empFname, empLname, deptID(FK) and
Department: deptID(PK), deptName, chairID
chairID is empID from Employee table
Insert at least 3 rows in the Department table and at least 6 rows in the Employee table.
Create trigger on update of chairID that enforces the following business rules
One employee can chair no more than one department.
Each department has exactly one chair.