是我在3nf的表

Question

i have simple table with the following structure ID(PK) , title, director, year of production, production company

in 3nf, there must be no transitive relation between non primary keys, but i think (director, year of production and production company ) is dependent on title, but title itself cannot be a primary key in separate table since titles are not unique,

so is my table in 3nf or what ?

Answer 1

Your director, year of production, and production company are not dependent on title but on the film ID (assuming the subject matter is in fact films). The same film title (say "Robin Hood" or "Peter Pan" or "Tarzan") could appear several times in the table, but the director information depends on the film ID, not the title.

Your table is in 3NF -- unless you allow for multiple directors on a single film, or multiple production companies, or films that take several years to produce.