Creating Primary Key

[acct98]

I know this may be a silly question but I have to ask. Is it possible to set up a unique primay key in Oracle using a combination of fields (When used together this would create a unique key)? If yes -- Please provide example. Any assistance would be greatly appreciated.

 

[desiindian]

Hi,

I you are creating a table

create table test (
a varchar2(10),
b varchar2(10),
c varchar2(10),
constraint pk_test
primary key (a,b) );

If you are creating a unique index

create unique index ind_test on
test (a, b) ;

Hope this helps.

 

[svictor]

primary key would be a really good way to approach this problem.
But what if you have 12 fields that you need to combine into a primary key. Are there any know performance issues that I should be aware of?

The reason why I am asking is because I have to figure out a way of having two merge two identical DBs, where some of the tables do not have a unique key. So, I need to compare record to record in both tables and then, based on that if they are the same, delete one.

I am sure this kind of merge functionality has been written over and over again - do you know of any code to do this?
Thanks,
Vic
victor@starsystems.co.jp