570 views
2 votes
2 votes

1 Answer

Best answer
2 votes
2 votes

Assuming many to many relation i.e. 

An employee can work in multiple departments and a department has more than one employees

In that case each of the three tables(relations) mentioned will remain separate ; i.e. neither of them can be merged to other..In that case  eid of "works" relation (which is a table of relationship between emp and dept entities) which is referencing to "employee" relation and did which references to "dept" relation.. 

Considering the case that a manager is also an employee so manager_id should be a valid eid..Hence manager_id should reference to eid..Hence manager_id can also be a foreign key under this scenario..

Hence number of foreign keys possible   =   3  for the mentioned scenario..

selected by

Related questions

0 votes
0 votes
0 answers
1
srestha asked Sep 16, 2017
493 views
How one to many relation refers a foreign key?
5 votes
5 votes
1 answer
2
set2018 asked Nov 12, 2017
3,938 views
consider the following relational schema R(ABCDE) .The number of super keys in relation R if every two attributes of relation R is candidate keys are ___________
1 votes
1 votes
3 answers
3
stblue asked Sep 1, 2017
442 views
Primary key is subset or proper subset of superkey ?
2 votes
2 votes
1 answer
4