I need add data from a db in the google charts script, someone know how do? i'm programming in ruby on rails

[Miguel Angel Hernández Gómez]

google.charts.load('current', {'packages':['line']});

    google.charts.setOnLoadCallback(drawChart);

  function drawChart() {

    var data = new google.visualization.DataTable();

    data.addColumn('string', 'string');

    data.addColumn('number', 'The Avengers');

    data.addColumn('number', 'Transformers: Age of Extinction');

    data.addRows([

      ['line',  37.8, 80.8],

      ['line',20,20],

      ['line',  14.2, 13.4]

    ]);

    var options = {

      chart: {

        title: 'Box Office Earnings in First Two Weeks of Opening',

        subtitle: 'in millions of dollars (USD)'

      },

      width: 900,

      height: 500

    };

    var chart = new google.charts.Line(document.getElementById('grafica'));

    chart.draw(data, options);

  }