On Thu, Feb 14, 2008 at 12:45 PM, Derek Atkins <[EMAIL PROTECTED]> wrote:
> Mark Johnson <[EMAIL PROTECTED]> writes: > > > Phil Longstaff wrote: > >> The slot_id is used to provide a unique primary key. I don't know if > it > >> would work to have the slots table have *no* key, but have an index on > >> the obj_guid field. The obj_guid field can't be the primary key > because > >> I believe a primary key needs to be unique. Mark? > >> > >> > > Yes, a primary key does have to be unique. I can't think of any > > requirement that a table have a primary key though. It is generally > > good practice. You could have an index on the guid field. > > I think the question was more: Does every table have to HAVE > a primary key? no. The SQL spec does not require a primary key. Yes, the primary key must be unique, but what > if a table has no primary key? Is that still okay? yes, it is ok, though performance will usually suffer. Nathan > > > -derek > -- > Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory > Member, MIT Student Information Processing Board (SIPB) > URL: http://web.mit.edu/warlord/ PP-ASEL-IA N1NWH > [EMAIL PROTECTED] PGP key available > _______________________________________________ > gnucash-devel mailing list > gnucash-devel@gnucash.org > https://lists.gnucash.org/mailman/listinfo/gnucash-devel > -- <><><><><><><><><><><><><><><> "Even if you are on the right track, you'll get run over if you just sit there" - Will Rogers _______________________________________________ gnucash-devel mailing list gnucash-devel@gnucash.org https://lists.gnucash.org/mailman/listinfo/gnucash-devel
