0
votes
4answers
82 views

SqlServer: can one table's PK be the FK of other two table's? [duplicate]

I have three tables project, users and proj_user. The PK of proj_user table is the FK of project and users table's pk e.g.(project_id,user_id) My question is, is it possible for the project_id and ...
1
vote
1answer
56 views

What problem prevents well defined behavior of a foreign key on a non-unique column?

In my noob opinion, it strikes me that in a serialized environment, this shouldn't be a problem. Is that correct? If not, please explain to me why a foreign key's behavior on a non-unique column is ...
2
votes
1answer
413 views

MySQL Unique Index Keylength

I am hashing keys from one table that provides a 256 bit (64 char length) alphanumeric string that I intend to use in a second table as a foreign key. The engine of choice here is InnoDB. There are ...