Re: Find most recent rows, generically?

Hi all,

First of all, some clarification is in order: With MS SQL Server, 'identity' serves as an attribute to integer or other numberic data type, it IS NOT a data type by itself, and I never said 'identity' is a data type. Secondly, again, assume we don't know if there's a date column in the table. The question was really, how to determine if Oracle 'sequence' exists for a given column, say, PK column (EMPNO) for EMPLOYEE table, and if so, where to find the 'sequence' numbers for that column (EMPNO)? Thanks.

DL

"Jim Kennedy" <kennedy-family_at_attbi.com> wrote in message news:<EJgc8.5529$S01.352296_at_sccrnsc02>...
> There are sequences in Oracle and you could store them as integers, numbers,
> strings, but there is not a column type of identity. That is you cannot
> look at the column type and determine that it is a sequence. Sequences are
> nice because if I have a table with a bunch of child tables I can insert a
> record in the parent and then use that value (mySequence.currentval ) for
> the related keys in the child tables.
>
> If you need to know what the most recent rows are I think a date column is a
> much better use. Then you could know when. You might be interested in how
> many rows are generated per day which a sequence won't tell you.
> Jim
>
> "DL" <donlcs_at_yahoo.com> wrote in message
> news:604bb90c.0202172222.a375f10_at_posting.google.com...
> > Thanks for the response, Jim, let me re-phrase my question, with MS
> > SQL Server, when I add a column and define it as integer, identity,
> > later I can find out if that column is of data type int etc., what's
> > Oracle's equivalent of "Identity" if any? and if yes, which system
> > table do I go to determine it? Thanks.
> >
> > DL
> >
> > "Jim Kennedy" <kennedy-family_at_attbi.com> wrote in message
 news:<9qhb8.431$Ot2.153407_at_sccrnsc01>...
> > > You can't. If it is important to know if it was recent then you need a
> > > column to model that attribute.
> > > Jim
> > > "DL" <donlcs_at_yahoo.com> wrote in message
> > > news:604bb90c.0202150930.49ef0fc5_at_posting.google.com...
> > > > Hi,
> > > >
> > > > First of all, I thank those who have been very helpful in the past.
> > > > How to find most recent rows, say, 10, (for insert and update
> > > > transactions), generically?
> > > >
> > > > For insert:
> > > > Well, one can find PK column of a given table, suppose, single column,
> > > > then determine data type of that column, if it is of integer or
> > > > similar type data,
> > > > 1(a) how would one know that it uses "identity" attribute for it
> > > > (thus, incremental)?
> > > > 1(b) and if it does not, how to proceed?
> > > > 2, what if it is of random alphnumeric?
> > > > 3, what if it is of composite keys?
> > > >
> > > > For update:
> > > > ???
> > > >
> > > > * Question category 1 is most important to me for now.
> > > >
> > > > Thanks.
> > > >
> > > > DL
Received on Wed Feb 20 2002 - 05:08:28 CET