contactExport.js

function export_connect_csv(user_id, file_location){
  mysqlPool.getConnection(function(err, connection){
    var csv_row = "Email,First Name,Last Name,Status,Created\n";
    function processRow (row) {
      var csv_row = row.email+','+row.first_name+','+row.last_name+','+row.status+','+row.created+"\n";
      fs.appendFile(file_location, csv_row, function (err) {
        if(err){
          throw err;
        }
      });
    }
    fs.appendFile(file_location, csv_row, function (err) {
      if(err){
        throw err;
      }
      var query = connection.query('SELECT * FROM contacts where user_id = "'+user_id+'"');
      query
        .on('error', function(err) {
          //handle error
        })
        .on('fields', function(fields) {

        })
        .on('result', function(row) {
          processRow(row);
        })
        .on('end', function() {
          //email now
          
          console.log('done');
        });
    });
  });
}

var exportContacts = function(req, res){
  var user_id = req.params.user_id || 0;

  export_connect_csv(user_id);
  res.json({});
};