Dump big rows using CI return error memory limit

PHP Code:

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Migration extends CI_Controller {
    
    function test_ci()
    {
        ini_set('memory_limit', '2048M'); //i even tried -1 (my RAM is 8Gb)
        $this->db->save_queries = FALSE; //just make sure save_queries disabled
        $q = $this->db->query("SELECT * FROM mytable"); 
        echo $q->num_rows(); 
    }
    
    function test_native(){
        $serverName = "****";
        $connectionInfo = array( "Database"=>"****", "UID"=>"****", "PWD"=>"****" );
        $conn = sqlsrv_connect( $serverName, $connectionInfo);
        $sql = "SELECT * FROM mytable";
        $stmt = sqlsrv_query( $conn, $sql , [], ["Scrollable" => SQLSRV_CURSOR_KEYSET] );
        echo sqlsrv_num_rows( $stmt );
    }
    
} 


my database.php

PHP Code:

$active_group = 'default';
$query_builder = TRUE;

$db['default'] = array(
    'dsn'    => '',
    'hostname' => '***',
    'username' => '***',
    'password' => '***',
    'database' => '***',
    'dbdriver' => 'sqlsrv',
    'dbprefix' => '',
    'pconnect' => FALSE,
    'db_debug' => (ENVIRONMENT !== 'production'),
    'cache_on' => FALSE,
    'cachedir' => '',
    'char_set' => 'utf8',
    'dbcollat' => 'utf8_general_ci',
    'swap_pre' => '',
    'encrypt' => FALSE,
    'compress' => FALSE,
    'stricton' => FALSE,
    'failover' => array(),
    'save_queries' => FALSE //disabled save_queries
); 


i want to dump all my rows (180k++ rows) for several purpose (like migration, etc). But i always get memory_limit error. 

So i create 2 method to compared my problem:

test_ci = fatal error memory_limit blabla
test_native = 180k++

NOTE:

1. in this demo i just try to count rows to simplify the demo code. But in the real case i have have complex script to parse the result.
2. i can hack this using Limit clause. But i just want to know how to do this using CI.

i tried to googling this for an hour but still not get any luck.
did i miss something?

You would need to dump it out with phpMyAdmin.

You could then read and write out using CodeIgniter in chunks.

What did you Try? What did you Get? What did you Expect?

Joined CodeIgniter Community 2009.  ( Skype: insitfx )

While I agree with InsiteFX, my question is...did you check the PHP and CI error logs to see if you could get more information?