MySQL/PHP Database Normalisation -

im working amongst group of fellow students creating relational mysql database used in conjunction php.

we attempting normalise database , differing in opinion. when normalising , creating new table 2 of group, myself included feel best practice foreign key left behind in existing table unique identifier in new table becomes new pk.

the remainder of group have been taught/feel should implemented other way, i.e. primary key left behind.

could case long relationship present job, or case 1 method correct on other.

thanks in advance

gary

this depends on doing. when removing partial dependency rule is:

    r = (a, b, c, d)          , b makes composite primary key ,       c dependent on           r1 = (a, c)       r2 = (a, b, d)   

if removing transitive dependency then:

      r = (a, b, c)      primary key , c dependent on b       r1 = (a, b)      r2 = (b, c)