UniqueID and ID

Question

this is my first time working with DB in android. So I figured I would follow this tutorial http://www.androidhive.info/2012/01/android-login-and-registration-with-php-mysql-and-sqlite/

As you can see, it makes you create a DB which as both an ID and something called UNIQUE_ID (there's even a function in PHP which creates a unique identifier)

ID is the primary key UNIQUE_ID is set as UNIQUE

my question is. why do I need both? which one do I use for foreign keys?. Which is the point of having such a long a complicated ID?

Thanks In advance

score 0 · Answer 1 · answered Jan 24 '14 at 17:22

0

The first ID it is the primary key for the table which is mainly a unique counter that updates every time a new row is created. It will keep increasing even if the row gets deleted.

UNIQUE_ID is an identifier created to keep track of users; think of it as if it were a unique username field

answered Jan 24 '14 at 17:22

Emmanuel

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Thanks :) so, which one should I use link other tables together? – frankelot Jan 24 '14 at 17:28
I do not know what you mean. What do you want the tables to have in common? – Emmanuel Jan 24 '14 at 17:31
Well, I have these tables: ALBUMS - SONGS. Inside songs I have a column called 'in_album' in which I want to store the album ID. Which ID should I store. the UNIQUE_ID or just the ID. – frankelot Jan 24 '14 at 17:37
You need to store the ID that represents the album, not the row ID. – Emmanuel Jan 24 '14 at 18:29

UniqueID and ID

1 Answers1