CODEWITHSUNDEEP
codeigniterdatabase-migration
YahyaE
YahyaE

Reputation: 1057

Codeigniter Migration cannot redeclare class

I am trying to add reset function to codeigniter's migration. Below is my code:

class Migration extends Backend_Controller {

  public function __construct()
  {
    parent::__construct();
    $this->load->library('migration');
  }

  public function index()
  {
    //...
  }

  public function reset()
  {
    $this->migration->version(1);
    $this->db->truncate('ci_sessions'); 
    $this->migration->current();
  }

}

It returns error:

Fatal error: Cannot redeclare class Migration_Create_geo_data in D:\web_projects\vProject\framework\application\migrations\002_create_geo_data.php on line 44

If I run them seperately, all are okay. When together it gives error. Any idea?

Upvotes: 1

Views: 2404

Answers (2)

m79lkm
m79lkm

Reputation: 3070

Most likely, this error is a result of setting your migrations to create tables if they do not already exist AND cache data not being updated right away.

Your Migration script calls the DB_forge::create_table method which takes two parameters. Parameter one is the table name and parameter two is optional. It is the if_not_exists flag. The default value is false however; if it is set to true tables will only be created if they do not already exist.

If your tables are created with the if_not_exists parameter set to false the caching issue will (probably) never happen:

$this->dbforge->create_table('table_name');

If tables are created with the if_not_exists parameter set to true, you will need to force the cache to update when reloading your migrations.

$this->dbforge->create_table('table_name', TRUE);

Here are a couple options to avoid this issue:

  1. Only send the table name as a parameter to the create_table method
  2. Unset data_cache['table_names'] after the migration->version(0) call

If you choose option 2, here is a method that works:

public function reset() {
    $this->load->library('migration');

    if (!$this->migration->version(0)) {
        echo $this->migration->error_string();
    }

    // unset table cache - this will force it to update
    unset($this->db->data_cache['table_names']);

    if (!$this->migration->current()) {
        echo $this->migration->error_string();
    }
}

In addition to this, the migration files are autoloaded and saved in the session. I changed this line in system/libraries/Migration.php: include $f[0]; to include_once $f[0];

Upvotes: 2

jmadsen
jmadsen

Reputation: 3675

Most likely, you made a migration by copy/pasting from an earlier one & now have two migration files with the same class declared

ie, 

class Migration_Add_blog extends CI_Migration

in two files

Upvotes: 1

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