> A primary key is a unique way to identify one row in a table.
> to have several keys, but only one would be your primary key. For example,
> here in the UK, each adult has a different National Insurance number. If you
> were writing a payroll application, you might have an internal "payroll_id"
> column as well as a "ni_num" column. Both are unique but it might make more
> sense in the application to use "payroll_id" - this is a business decision.
And - if you agree with database theory - a bad one at that.
Supposedly primary keys should be void of any meaning bar
their primary key-ness. I got into the habit of starting
any but the most simple table like this:
create table (
id serial primary key,
...
Never had any trouble with that. Good or bad practice ? Gotta
decide for yourself.
Karsten
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