Question

I am starting a new Project for a website based on “Talents” – for example:

• Models
• Actors
• Singers
• Dancers
• Musicians

The way I propose to do this is that each of these talents will have its own table and include a user_id field to map the record to a specific user.

Any user who signs up on the website can create a profile for one or more of these talents. A talent can have sub-talents, for example an actor can be a tv actor or a theatre actor or a voiceover actor.

So for example I have User A – he is a Model (Catwalk Model) and an Actor (TV actor, Theatre actor, Voiceover actor).

My questions are:

1. Do I need to create separate tables to store sub-talents of this user?

2. How should I perform the lookups of the top-level talents for this user? I.e. in the user table should there be fields for the ID of each talent? Or should I perform a lookup in each top-level talent table to see if that user_id exists in there?

3. Anything else I should be aware of?

Answer 1

ok sorry for the incorrect answer.. this is a different approach.

The way i see it, a user can have multiple occupations (Actor, Model, Musician, etc.) Usually what i do is think in objects first then translate it into tables. In P.O.O. you’d have a class User and subclasses Actor, Model, etc. each one of them could also have subclasses like TvActor, VoiceOverActor… in a DB you’d have a table for each talent and subtalent, all of them share the same primary key (the id of the user) so if the user 4 is and Actor and a Model, you would have one registry on the Actor’s Table and another on the Model Table, both with id=4

As you can see, storing is easy.. the complicated part is to retrieve the info. That’s because databases dont have the notion of inheritance (i think mysql has but i haven’t tried it).. so if you want to now the subclases of the user 4, i see three options:

• multiple SELECTs for each talent and subtalent table that you have, asking if their id is 4.

  SELECT * FROM Actor WHERE id=4;SELECT * FROM TvActor WHERE id=4;

• Make a big query joining all talent and subtalent table on a left join

  SELECT * from User LEFT JOIN Actor ON User.id=Actor.id LEFT JOIN TvActor ON User.id=TvActor.id LEFT JOIN… WHERE User.id=4;

• create a Talents table in a NxN relation with User to store a reference of each talent and subtalents that the User has, so you wont have to ask all of the tables. You’d have to make a query on the Talents table to find out what tables you’ll need to ask on a second query.

Each one of these three options have their pros and cons.. maybe there’s another one =)

Good Luck

PS: ahh i found another option here or maybe it’s just the second option improved