Paul Lalli wrote:
On Oct 5, 9:09 am, [EMAIL PROTECTED] (Robert Hicks) wrote:
The scenario: I have a file with ship id numbers. It gets updated
several times a day (by database query) and I want to find all the
"new_ships" that have been added to it.
sub incremental_update {
print "Doing incremental update.\n";
open $FH, '+<', $ships_file or croak "Cannot open $ships_file!\n";
# Get all the ships in it
my @ships = do { local $/; <$FH> };
Are you aware each element of @ships has a newline attached? Is that
what you want?
my %seen = ( );
my @new_ships = ( );
There is no need to initialize arrays/hashes to ( ) explicitly. Perl
does that automatically.
I actually did know this but I was looking at other code at the time and
I brain farted. : )
foreach my $item (@ships) { $seen{$item} = 1 }
# Getall the LLY_NUMS from the table
$sql = qq{ SELECT LLY_NUM FROM AMVER_VESS WHERE ONPLOT_FLAG = 'T' };
$sth = $dbh->prepare( $sql );
$sth->execute or die "Can't execute SQL statement: $DBI::errstr\n";
while ( my @row = $sth->fetchrow->array ) {
foreach my $lly_num (@row) {
This is redundant. You have only one column in your SELECT clause.
Therefore @row will only contain one element. Eliminate one of the
loops, and make this:
while (my ($lily_num) = $sth->fetchrow->array()) {
unless ( $seen{$lly_num} ) {
# it isn't in %seen, so add it to @new_ships
push( @new_ships, $lly_num );
}
}
print $FH "@new_ships\n";
}
close $FH;
}
Cool, I learn something new every day with Perl. : )
Thanks!
Robert
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