> I'm hoping to get some feedback on how often updatable
> cursors are being used in DBI apps ?
We use it from timne to time. I have implemented them in DBD::Ingres (see
ing_readonly in the DBD::Ingres docs).
> My understanding is that "standard" embedded SQL uses a syntax like
> DECLARE CURSOR cursor-name AS select-stmt FOR UPDATE;
> OPEN cursor-name;
> FETCH cursor_name INTO ...;
> UPDATE table SET ... WHERE CURRENT OF cursor-name;
> (or DELETE FROM table WHERE CURRENT OF cursor-name)
With DBD::Ingres the syntax is:
$sth = $dbh->prepare("SELECT a,b,c FROM t FOR UPDATE OFb");
$sth->execute;
$row = $sth->fetchrow_arrayref;
$dbh->do("UPDATE t SET b='1' WHERE CURRENT OF $sth->{CursorName}");
where I assume that a select without a 'FOR UPDATE OF column' clause is
read-only.
Henrik Tougaard
DBD::Ingres maintainer.
