Jonathan Leffler wrote:
On Fri, Mar 14, 2008 at 5:53 AM, <[EMAIL PROTECTED]> wrote:
I have been playing about with scrollable result sets (Cursors)
in Oracle/OCI and have noticed that there has been some discussion about
it before on the list
You can find the discussion here
http://perl.markmail.org/search/?q=list%3Aorg.perl.dbi-dev+fetch_scroll#query:list%3Aorg.perl.dbi-dev%20fetch_scroll+page:1+mid:xqwmgau3zesiyo7n+state:results
and here
http://perl.markmail.org/search/?q=from%3A%22Tim+Bunce%22+scroll+cursor#query:from%3A%22Tim%20Bunce%22%20scroll%20cursor+page:1+mid:t3xvtu3rcqarszsx+state:results
Reading through these I see that basically each Database has its own
flavour or scrollable results set from a select i.e.
Informix Scrollable and updateable
MySQL semi Scrollable
Oracle Scrollable and read only
SQLServer Scrollable and read only
Scrollable and updateable
So my proposal is to stub in
fetch_scroll
in DBI
and let the DBD drivers write their own implementation
This would be the same as "bind_param_inout_array" which is stubbed in but
not implemented in DBI
The proposed sub would be like this
bind_param_inout_array => { U =>[1,2,'[, \%attr]'] }
so there will be an attribute param to pass in any commands/setting that
are needed for the fetch.
The advantage of this is we get something that would be customized for
each DBD implementation of course the disadvantage is we do not have a
pure Perl implementation of his functionality.
Any thoughts,comments or even insults;) are welcome
Sounds good to me. Will there be a standard set of 'scroll actions'?
FETCH_NEXT
FETCH_PREV
FETCH_FIRST
FETCH_LAST
FETCH_CURRENT
FETCH_RELATIVE
FETCH_ABSOLUTE
(Any others? That's the set for Informix.)
$sth->fetch_scroll(FETCH_xxx [, $offset]);
Or do we need a more general hash to pass values in?
In DBI's spirit of ODBC/SQL CLI conformance, presumably the
attributes should be
SQL_FETCH_NEXT
SQL_FETCH_PRIOR
SQL_FETCH_FIRST
SQL_FETCH_LAST
SQL_FETCH_ABSOLUTE
SQL_FETCH_RELATIVE
SQL_FETCH_BOOKMARK
with values as defined somewhere in ODBC's header files.
Gruesome details of ODBC's SQLFetchScroll are here:
http://msdn2.microsoft.com/en-us/library/ms714682(VS.85).aspx
Dean Arnold
Presicient Corp.
