Keys

[vasilek]

Hello. I understand what the Primiry Key is and can assume what is the Foreign Key. But, could someone explain what are the Alternate Keys, Compound Keys and Multi Line Keys in FileMaker relational database design?

Thank you very much!

FileMaker Version: 6

Platform: Windows 2000

[CyborgSam]

Alternate keys are just other pieces of data you relate to. Example: if the primary key is a unique serial #, a alternate key could be something like hair color.

Compound Keys are when you combine two or more fields into one key. This gets around FM6 and earlier having relationships based on a single key (field). If you wanted to match everyone born in July who has red hair, you could combine the two like this: NumToText(Month(DOB)) & "_" & Haircolor.

Multi-Line keys allow you to match more than one set of data at a time. Multi-Line keys must be text. Example: you want to match everyone with either red or brown hair. The related file has a single color for each person. in the main file, the key would contain red on one line and brown on another. This technique is very powerful, you can make calculations on both ends to match almost any combination of data.

This is quicky, you may also want to read FileMaker's "21 Secrets of FileMaker Pro", a PDF somewhere on their site...

[vasilek]

Thanks, CyborgSam for the good explanation!