title: How do I read a large csv file using exceljs
body: <p>I'm using <strong>exceljs</strong> with csv and excel files in my project. Recently the files become really large and I am having trouble to read them as normal. 
  The following code works good for small files however it can't read <strong>Million rows</strong>.</p>
  
  <p>I realized I need to use <strong>stream</strong> but I don't understand how it works. I would like to use it for the same case just to be able to read large. Can someone help please?</p>
  
  <pre><code>var Excel = require('exceljs');
  var workbook = new Excel.Workbook();
  readSecurityCSV(workbook);
  var header = {}
  var adSecurities = []
  
  
  
  function readSecurityCSV(workbook){
  workbook.csv.readFile('./csv/clientsOrders.csv')
  .then(worksheet =&gt; {
  
     worksheet.eachRow({ includeEmpty: true }, function(row, rowNumber) {
  
       if(rowNumber == 1){
         header = {}
         row.eachCell({ includeEmpty: true }, function(cell, cellNumber) {
           header[cellNumber] = cell
  
         });
       }else{
         var currentSecurity = {}
         row.eachCell({ includeEmpty: true }, function(cell, cellNumber) {
  
          currentSecurity[header[cellNumber].value] = cell.value
         });
  
         currentSecurity.rowNumber = rowNumber
  
         adSecurities.push(currentSecurity)
  
  
       }
  
     });
     console.log(color.blue("adSecurity"), adSecurities[0]);
  
   })
  
  }
  </code></pre>