It depends of DBD driver which you use.
This piece of code was tested for PostgreSQL and MYSQL:

   $sth = $dbh->prepare($query) or die "Prepare exceptioin: $DBI::errs
+tr!";
   $rv = $sth->execute() or die "Execute exception: $DBI::errstr";
   $res = $sth->fetchall_arrayref();                    
   
   # Array reference with cols captions, which were retrived.
   $names = $sth->{NAME};          
   
   # Array reference with types of cols, which  were retrived         
+             
   $types = $sth->{TYPE};                               
   $sth->finish();
[download]

For other database maybe it will be the same
but try to look at documentation for them DBD drivers.

      
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SV* sv_bless(SV* sv, HV* stash);