I am using mysql. The business requirement is that every Employee must be registered in a Department. However, every Department has to have one Manager to manage the department. As you can see, a Manager is an Employee itself, so, I only have two tables here, Employee and Department.
In the Employee table, I have a department column as a foreign key that refer to the Department table which I gave a NOT NULL constraint as it's a total participation. In the Department table, I have the manager column which I also gave a NOT NULL constraint as it's also a total participation.
The initial state of both tables are empty like usual however, now I can't insert data into the Employee table as I need to fill the department column which is impossible as the Department table is still empty. Then, I went to fill the Department table and it also doesn't work as the manager column cannot be empty and there is no record in the Employee table.
Help? :'(
