If you want to obtain db data in specified order, use fetchrow_arrayref() or similar functions.

my @keys=qw(e1 e2 e3 e4);
...
my $result_href = $sth->fetchrow_hashref ...
my @values = @{$result_href}{@keys};
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By definition, the keys in a hash are unordered.

If you need to work with columns in a particular order, simply create a separate array-variable containing the column names in the order that you need.   (Construct this array in the same logic that is building the SELECT statement.)   Then, iterate through that array to get each successive column-name, and use that column-name to fetch the data from the hash.

Notice that the order of the columns in the SELECT statement will no longer matter:   the only thing that matters is the order of the names in the array.

In the spirit of creating robust, reliable, self-diagnosing code, you should verify that every column-name you’re looking for does, in fact, exist in the row-data hashref.   It would be an extremely easy thing to make a “tpyo” here, with the consequence that a column of data would never show up in the output... and, maybe, no one would immediately notice the bug.   The code should assert that every single column-name must exist (even if the value is NULL), and, IMHO, should die if it does not.

Thank you for the reply. The reason for not using fetchrow->arrayref is we require the column names as well We need to pass the entire resultset (Column names & column values) to a hash which prints it to the file. The extract from the script is given below

$stmt = $dbh->prepare("$sql17");
$stmt->execute();
if($DBI::errstr)
{
     warn "Execution of SQL failed: $DBI::errstr\n";
     $dbh->rollback;
     closeOracleConnection($dbh);
}
else
               
@rowData = $stmt->fetchrow_array();
                $rowcnt = $#rowData;
                for ($i = 0; $i < $rowcnt; $i++)  {
                       @rs = $stmt->fetchrow_hashref();
                        push(@retArray,@rs);
                }
$stmt->finish;
        if ($#retArray == -1) {
                print (stdout "\nCould not generate values\n");
                exit (-1);
        }
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Need your valuable inputs to resolve this

I am not sure, what output data structure you require. Please, can you specify it?

Use fetchrow_arrayref() or fetchrow_array() with positions (0,1,2,3,4...), or if you feel like pre-defining the variables, use bind_col() or bind_columns().

See:
http://search.cpan.org/~timb/DBI/DBI.pm#fetchrow_arrayref
http://search.cpan.org/~timb/DBI/DBI.pm#bind_col

Hence my suggestion, above, that the simplest approach is simply to remove any assumptions (hence, dependencies) upon the order of the field-names in the query.     Since you have full control over the entire procedure, simply deal with the two problems separately.   The SELECT statement only need make sure that the necessary columns are returned.   Build a separate (Perl) list containing the column-names in the order that you need to present them.   Then, iterate through that list.   Problem (neatly) solved.

$emp_qry->execute();
while ( my $emprec = $emp_qry->fetchrow_hashref ) {
    $tmp_e1 = $emprec->{e1};
    $tmp_e2 = $emprec->{e2};
    $tmp_e3 = $emprec->{e3};
    $tmp_e4 = $emprec->{e4};
}
$emp_qry->finish();
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