what is PF?

Harrold

Registered User.
Local time
Today, 15:35
Joined
Mar 17, 2011
Messages
72
Hi

I understand that PK = Primary Key, FK = Foreign Key. but, what is PF?

Thanks
 
Not sure - in what context? Where are you seeing this?
 
Primary Foreign - a primary key that is also a foreign key :confused:
Personal Finance - :)
 
page faults, picofarads, provident fund - many possibilities
 
Ah, I see it now Alan. I guess I had the idea too :D
 
Have a look at the link posted by Alansidman in post #6. It explains what PF stands for. It's just a terminology used on that website. I don't know it to be a standard database terminology.
 
In some ways to me a primary foreign is a better name for FK than FK
 
Foreign Key makes more sense to me. It is a key value but it is not primary in the subordinate table.
 
Actually in the link provided by Alansidman, they have PK, FK and PF. PF is a part of a composite key that is also a PK in another table. PF's exist mainly in junction tables.
 
The explanation in the link suggests that PF means that the key is part of the Primary Key for the table where it appears as well as being a Foreign Key.

Junction tables often have a composite primary key made up of the foreign keys from the tables they are joining because they represent a unique combination of records from the other two tables.

However it is also possible for junction records to use duplicate combination of the junction FKs plus other fields. In these cases the junction table's primary key would also include one or more of those other fields.

For example a combination of the FKs EmployeeID, TaskID plus a Date. In this circumstance the junction table would indicate PF, PF, PK respectively.
 

Users who are viewing this thread

Back
Top Bottom