How to store something like Facebook Groups in DB?

Discussion in 'Databases' started by tlshaheen, Mar 7, 2010.

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  1. #1
    On Facebook, you can join/become a fan of groups. How do they keep track of things like that?
    For my use, I'm looking at having users become a fan of different things.
    Would you store it like this in the database:
    Table: Fans
    Columns: User_ID || Fan_Of (ID of group is stored here) || ID (Primary key? can't see ever using this field for any output...)
    Row: 1 || 3 || 1
    Row: 1 || 5 || 2
    Row: 1 || 4 || 3
    Row: 3 || 9 || 4

    Where each time a user becomes a fan of something, they get a a new row in the table.

    Is there a more efficient way of doing this? Thanks in advance!

    P.S.
    In the same topic (I think), would you store comments on a article the same way?
    Table: Comments
    Columns: User_ID || Article_ID || Comment || ID (Primary key? can't see ever using this field for any output...)
    Row: 1 || 3 || "Great article!" || 1
    Row: 1 || 5 || "Good job!" ||2
    Row: 1 || 4 || "Impressive!" || 3
    Row: 3 || 9 || "Good job!" || 4
     
    tlshaheen, Mar 7, 2010 IP
  2. killaklown

    killaklown Well-Known Member

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    #2
    you wouldnt need the last column if 'Fans', just make User_ID + Fan_Of the primary key. For Comments wouldnt Article_ID be the primary key?
     
    killaklown, Mar 7, 2010 IP
    tlshaheen likes this.
  3. tlshaheen

    tlshaheen Peon

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    #3
    Article_ID couldn't be the PK, no, because there would be more than 1 comment on an article!
    I forgot about composite keys (Duh!), thank you! For the Comments table, adding a datetime column could make my PK User_ID+Article_ID+Datetime the PK.

    Thanks!
     
    tlshaheen, Mar 7, 2010 IP