Table Emp

empno (pk)
fname
lname
hiredate

Table dept

deptid (pk)
deptname

Table Emp_dept

empno (fk)
deptid (fk)
fromdate
todate


Above is the scenario which is confusing me and i need help. As you can see the Emp_dept table has both the empno and deptid as foreign key.

I am confused that wheather a primary key to be established for this table or is it ok as is?

Would someone help plz.

yes, the PK for that table would be the first three columns

the PK would not prevent logical inconsistencies, but it's better than no PK at all