Re: Sequences?

And Oracle can cache in memory a number of numbers so that they do not serialize transactions the way autonumbering does.

Daniel Morgan

Jim Kennedy wrote:

> It's magic.
> Sequences are controlled by the database and doled out as you ask for them
> eg mysequence.nextval
> Jim
> "Bruce" <bghagy_at_attbi.com> wrote in message
> news:YZFa8.53731$Pz4.283117_at_rwcrnsc53...
> > What's the mechanism to keep the value unique? If another SELECT is run
> > before the first INSERT wouldn't that give you two equal values?
> >
> >
> > "damorgan" <dan.morgan_at_ci.seattle.wa.us> wrote in message
> > news:3C6A966C.5E02C7DF_at_ci.seattle.wa.us...
> > > There is no relationship between MS Access's autonumbering and a
> SEQUENCE.
> > The
> > > autonumering is part of the table and is only capable of sequential
> > numbering.
> > > It has no flexibility, no programmability, and is strictly tied to a
> > single
> > > table. All it is is the following code built in and hidden from the end
> > user.
> > >
> > > SELECT MAX(numbering_field)
> > > INTO next_number
> > > FROM xyz;
> > >
> > > INSERT INTO xyz
> > > (numbering_field + 1, other_field1, other_field2)
> > > VALUES
> > > (next_number, someval1, someval2);
> > >
> > > Daniel Morgan
> > >
> > >
> > >
> > > Magnus Ytterstad wrote:
> > >
> > > > Not sure how MS Access autonumber works, but it does sound like a
> > sequence
> > > > to me.
> > > >
> > > > To create a sequence use the following syntax
> > > >
> > > > CREATE SEQUENCE MYSEQUENCE INCREMENT BY 1 START WITH 1000;
> > > >
> > > > When you want to access the sequence and get the next number, you just
> > issue
> > > > the command MYSEQUENCE.NEXTVAL, i.e.:
> > > >
> > > > INSERT INTO MYTABLE (NAME, DEPT, ID)
> > > > VALUES ('John', 'Sales', MYSEQUENCE.NEXTVAL);
> > > >
> > > > Hope this helps!
> > > > -magnus.
> > > >
> > > > Bruce <bghagy_at_attbi.com> wrote in message
> > > > news:gP3a8.39737$bh3.256829_at_rwcrnsc52.ops.asp.att.net...
> > > > > How would one go about implementing the MS Access autonmuber data
> type
> > in
> > > > > 8i? Are sequences the way to go and could you point me in the right
> > > > > direction.
> > > > >
> > > > >
> > >
> >
> >
Received on Thu Feb 14 2002 - 11:18:44 CST