CODEWITHSUNDEEP
phpdatabasecodeignitermigration
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Reputation: 400

Create database with codeigniter's migration class

I want to integrate Codeigniter's migration class to my project's build process. Can i use the migration class to create databases, or it's only purpose to keep up to date the database structure?

My migration class looks like this:

class Migration_base extends CI_Migration {
 public function up()
 {
   $this->dbforge->create_database('my_db');
 }
 public function down()
 {
   $this->dbforge->drop_database('my_db');
 }
}

When i run this code:

class Migrate extends CI_Controller
{
    public function index()
    {
            $this->load->library('migration');

            if ($this->migration->current() === FALSE)
            {
                    show_error($this->migration->error_string());
            }
        }

}

I get this message:

Database error: A Database Error Occurred
        Unable to connect to your database server using the provided settings.
        Filename: path_to_codeigniter/codeigniter/framework/system/database/DB_driver.php
        Line Number: 436

It seems the database must already exist before I can use migration class. Am I correct and need to write a wrapper around migration class where i create the database first?

Upvotes: 1

Views: 1978

Answers (1)

DFriend
DFriend

Reputation: 8964

Your suspicion that a workaround will be needed in order to create a database as part of a migration seems to be true. I don't know if it could be called a bug or missing feature but it will not do it as written.

The big issue is that the _migration_table that the class creates needs to be in the database being migrated. A classic "chicken or egg" problem.

Another possible issue, something the documentation assumes and doesn't address, is that the database to be migrated is the one that should be "loaded".

I think the following version of your Migrate controller will handle both of those issues.

class Migrate extends CI_Controller
{
    public function index()
    {
        if( ! isset($this->db))
        {
            throw new RuntimeException("Must have a database loaded to run a migration");
        }

        // Are we connected to 'my_db' ?
        if( ! $this->db->database !== 'my_db')
        {
            //find out if that db even exists
            $this->load->dbutil();
            if( ! $this->dbutil->database_exists('my_db'))
            {
                // try to create 'my_db'
                $this->load->dbforge();
                if( ! $this->dbforge->create_database('my_db'))
                {
                    throw new RuntimeException("Could not create the database 'my_db");
                }
            }

            // Connection data for 'my_db' must be available 
            // in /config/database.php for this to work.
            if(($db = $this->load->database('my_db', TRUE)) === TRUE)
            {
                $this->db = $db;  //replace the previously loaded database
            }
            else
            {
                throw new RuntimeException("Could not load 'my_db' database");
            }
        }

        $this->load->library('migration');

        if($this->migration->current() === FALSE)
        {
            show_error($this->migration->error_string());
        }
    }
}

Please know I have not tested this code. There may be syntax, logic or other errors. If nothing else, hopefully, it gives you a good starting place

Upvotes: 3

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