Terry Lee Tucker <terry(at)esc1(dot)com> writes:
> From the HTML docs:
> "The referenced columns must be the columns of a unique or primary key
> constraint in the referenced table."
> I personally don't know of a work around. Maybe some of the others do.
There is no workaround, because foreign keys don't make any sense if
there isn't a uniquely identifiable referenced row.
regards, tom lane