Simple code to fetch selected data from database table in excelsheet in cakephp:

Step 1: To achieve this we will use csvHelper class. Now make a file named as CsvHelper.php in your app/View/Helper directory, then add the following code written below:

<?php
class CsvHelper extends AppHelper
{
var $delimiter = ',';
var $enclosure = '"';
var $filename = 'Export.csv';
var $line = array();
var $buffer;

function CsvHelper()
{
    $this->clear();
}
function clear()
{
    $this->line = array();
    $this->buffer = fopen('php://temp/maxmemory:'. (5*1024*1024), 'r+');
}

function addField($value)
{
    $this->line[] = $value;
}

function endRow()
{
    $this->addRow($this->line);
    $this->line = array();
}

function addRow($row)
{
    fputcsv($this->buffer, $row, $this->delimiter, $this->enclosure);
}

function renderHeaders()
{
    header('Content-Type: text/csv');
    header("Content-type:application/vnd.ms-excel");
    header("Content-disposition:attachment;filename=".$this->filename);
}

function setFilename($filename)
{
    $this->filename = $filename;
    if (strtolower(substr($this->filename, -4)) != '.csv')
    {
        $this->filename .= '.csv';
    }
}

function render($outputHeaders = true, $to_encoding = null, $from_encoding ="auto")
{
    if ($outputHeaders)
    {
        if (is_string($outputHeaders))
        {
            $this->setFilename($outputHeaders);
        }
        $this->renderHeaders();
    }
    rewind($this->buffer);
    $output = stream_get_contents($this->buffer);

    if ($to_encoding)
    {
        $output = mb_convert_encoding($output, $to_encoding, $from_encoding);
    }
    return $this->output($output);
}
}
?>

Step 2: Now create a method export() in your controller class. export method is used to fetch selected data from your database table.

function export()

{

$this->set('posts', $this->Post->find('all'));

$this->layout = null;

$this->autoLayout = false; Configure::write('debug','0');

}

Step 3: Next, In your controller(ex: PostController) add the following line of code:

var $helpers = array('Html', 'Form','Csv');

Step 4: Now we will create a file named export.ctp in app/View/ your controller to write resulting data in th excel sheet.

<?php

$line= $posts[0]['Post'];
$this->CSV->addRow(array_keys($line));
 foreach ($posts as $post)
 {
   $line= $post['Post'];
   $this->CSV->addRow($line);
 }
 $filename='posts';
 echo  $this->CSV->render($filename);
?>

Step 5: Last but not least create a link named export, on clicking the link you can get the data from your database table in excel sheet.

<?php echo $this->Html->link('Export',array('controller'=>'posts','action'=>'export'), array('target'=>'_blank'));?>