Hi,
Do you mean that the table has two unique indices, or that the primary index
has two columns?
Either way, it is easy to define this in mysql:
create table foo (
col1 varchar(20) not null,
col2 int not null,
col3 smallint not null,
primary key(col1, col2),
unique second_idx(col1, col3));
It's ok for a table to have 2 keys that COULD be the PIKE. only 1 of them
can actually BE the PIKE, the other is a Candidate Key. (CK)
As to whether you should make them both part of the PK, that's a different
question. I usually avoid compound PK's unless there is NO OTHER WAY AROUND
IT.
Cal
