Re: ER question

bcjm wrote:
>
> Say you have two tables, emp and dept. emp has dept_id foreign key
> which references dept table. What if I need to tract who is the
> department head? Do you add the emp_id to the dept table or do you
> create a indicator flag field in the emp table? Which way is better
> and why. Hope my question is clear.
>
> Thanks

The entity DEPT has a department head as one of its attributes. So the department head should be a column in the DEPT table. Since that department head is also an employee, you will most likely want a FK relationship between the dept head column in DEPT and the EMP_ID column of the EMP table.

HTH,
Brian

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