make it easier to update prices.db

djia-vs-gold-ratio/djia-load.pl

@@ -5,14 +5,19 @@
 use Text::CSV_XS;
 use DBI;
 
+require 'utils.pl';
+
 my $dbh = DBI->connect("dbi:SQLite:dbname=prices.db", "", "") or die DBI->errstr;
+my $last_date = last_date($dbh, 'DJIA');
 
 for my $file (@ARGV) {
   my $csv = Text::CSV_XS->new({ binary => 1 })
     or die "Cannot use CSV: " . Text::CSV->error_diag();
   open my $fh, "<:encoding(utf8)", $file  or die "$file: $!";
+  $csv->getline($fh); # throw away first line
   while (my $row = $csv->getline($fh)) {
     my ($date, $open, $high, $low, $close) = @$row;
+    next unless $date gt $last_date;
     $dbh->do(
       "INSERT INTO price (symbol, value, day) VALUES ('DJIA', ?, ?)", {},
       $close, $date

djia-vs-gold-ratio/gold-load.pl

@@ -6,6 +6,8 @@
 use DBI;
 use Data::Dump 'pp';
 
+require 'utils.pl';
+
 my %month_number = (
   Jan => '01',
   Feb => '02',
@@ -32,6 +34,7 @@ sub date {
 }
 
 my $dbh = DBI->connect("dbi:SQLite:dbname=prices.db", "", "") or die DBI->errstr;
+my $last_date = last_date($dbh, 'XAU');
 
 for (@ARGV) {
   my $parser = Spreadsheet::ParseExcel->new();
@@ -42,11 +45,13 @@ sub date {
   for my $row ($min .. $max) {
     my $date_cell = $daily_gold->get_cell($row, 0);
     my $usd_cell  = $daily_gold->get_cell($row, 1);
+    my $date      = date($date_cell->value);
+    next unless $date gt $last_date;
     #print date($date_cell->value), " -- ", $usd_cell->value, "\n";
     $dbh->do(
       "INSERT INTO price (symbol, value, day) VALUES ('XAU', ?, ?)", {},
       $usd_cell->value,
-      date($date_cell->value)
+      $date
     );
   }
 }

djia-vs-gold-ratio/utils.pl

@@ -0,0 +1,11 @@
+use strict;
+use warnings;
+use DBI;
+
+sub last_date {
+  my ($dbh, $symbol) = @_;
+  my ($last) = $dbh->selectall_arrayref("SELECT max(day) as day FROM price WHERE symbol = ?", { Slice => {} }, $symbol);
+  $last->[0]{day};
+}
+
+1;