Try

#!/usr/bin/perl
use strict;
use DBI;
use GD::Graph::Data;
use GD::Graph::bars;

my $batchnumber = '20170903nervana';

my $sql = '
  SELECT time, mastuntemp, LineTemp, spargtemp 
  FROM brew_temp_tb 
  WHERE sitename = ? 
    AND batchnumber = ?
  ORDER BY time';

my $dbh = dbh(); # connect
my $sth = $dbh->prepare($sql);
$sth->execute('Brew',$batchnumber);           
           
my $data = GD::Graph::Data->new();
while (my @row = $sth->fetchrow_array){
  $data->add_point(@row);
}

my $chart = GD::Graph::bars->new();
my $gd = $chart->plot($data);
open(IMG, '>','bar.png') or die $!;
binmode IMG;
print IMG $gd->png;

# connect
sub dbh{
  my $database = "test"; 
  my $user     = "user"; 
  my $pw       = "password";
  my $dsn = "dbi:mysql:$database:localhost:3306"; 
  my $dbh = DBI->connect($dsn, $user, $pw, 
     { RaiseError=>1, AutoCommit=>1 } );
  return $dbh;
}

[download]
poj

In reply to Re^5: Getting mysql data into gd by poj
in thread Getting mysql data into gd by shanta

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.