[SQL] question : the choice of the primary key.

2004-01-08 Thread Loeke
U have for example something like this create table persons( (id..), surename .., familyname .., street .., .., birthdate,.. ) a table containing the data of persons, each persons should of course be present only once; and one should still define a primary key, there are two options now, 1.many p

Re: [SQL] question : the choice of the primary key.

2004-01-08 Thread Loeke
> 1.many people make an extra id field and choose this id field to be the > p-key, > but then the same person can be present twice in the table (with different > id fields), the id in itself has no real meaning > 2.or u can choose the "natural" key for each person, lets say a name and the > birthda