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Diffstat (limited to 'user_guide_src/source/libraries/migration.rst')
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diff --git a/user_guide_src/source/libraries/migration.rst b/user_guide_src/source/libraries/migration.rst deleted file mode 100644 index 97c72303c..000000000 --- a/user_guide_src/source/libraries/migration.rst +++ /dev/null @@ -1,184 +0,0 @@ -################ -Migrations Class -################ - -Migrations are a convenient way for you to alter your database in a -structured and organized manner. You could edit fragments of SQL by hand -but you would then be responsible for telling other developers that they -need to go and run them. You would also have to keep track of which changes -need to be run against the production machines next time you deploy. - -The database table **migration** tracks which migrations have already been -run so all you have to do is update your application files and -call ``$this->migration->current()`` to work out which migrations should be run. -The current version is found in **application/config/migration.php**. - -.. contents:: - :local: - -.. raw:: html - - <div class="custom-index container"></div> - -******************** -Migration file names -******************** - -Each Migration is run in numeric order forward or backwards depending on the -method taken. Two numbering styles are available: - -* **Sequential:** each migration is numbered in sequence, starting with **001**. - Each number must be three digits, and there must not be any gaps in the - sequence. (This was the numbering scheme prior to CodeIgniter 3.0.) -* **Timestamp:** each migration is numbered using the timestamp when the migration - was created, in **YYYYMMDDHHIISS** format (e.g. **20121031100537**). This - helps prevent numbering conflicts when working in a team environment, and is - the preferred scheme in CodeIgniter 3.0 and later. - -The desired style may be selected using the ``$config['migration_type']`` -setting in your *application/config/migration.php* file. - -Regardless of which numbering style you choose to use, prefix your migration -files with the migration number followed by an underscore and a descriptive -name for the migration. For example: - -* 001_add_blog.php (sequential numbering) -* 20121031100537_add_blog.php (timestamp numbering) - -****************** -Create a Migration -****************** - -This will be the first migration for a new site which has a blog. All -migrations go in the **application/migrations/** directory and have names such -as *20121031100537_add_blog.php*. -:: - - <?php - - defined('BASEPATH') OR exit('No direct script access allowed'); - - class Migration_Add_blog extends CI_Migration { - - public function up() - { - $this->dbforge->add_field(array( - 'blog_id' => array( - 'type' => 'INT', - 'constraint' => 5, - 'unsigned' => TRUE, - 'auto_increment' => TRUE - ), - 'blog_title' => array( - 'type' => 'VARCHAR', - 'constraint' => '100', - ), - 'blog_description' => array( - 'type' => 'TEXT', - 'null' => TRUE, - ), - )); - $this->dbforge->add_key('blog_id', TRUE); - $this->dbforge->create_table('blog'); - } - - public function down() - { - $this->dbforge->drop_table('blog'); - } - } - -Then in **application/config/migration.php** set ``$config['migration_version'] = 20121031100537;``. - -************* -Usage Example -************* - -In this example some simple code is placed in **application/controllers/Migrate.php** -to update the schema.:: - - <?php - - class Migrate extends CI_Controller - { - - public function index() - { - $this->load->library('migration'); - - if ($this->migration->current() === FALSE) - { - show_error($this->migration->error_string()); - } - } - - } - -********************* -Migration Preferences -********************* - -The following is a table of all the config options for migrations. - -========================== ====================== ========================== ============================================= -Preference Default Options Description -========================== ====================== ========================== ============================================= -**migration_enabled** FALSE TRUE / FALSE Enable or disable migrations. -**migration_path** APPPATH.'migrations/' None The path to your migrations folder. -**migration_version** 0 None The current version your database should use. -**migration_table** migrations None The table name for storing the schema - version number. -**migration_auto_latest** FALSE TRUE / FALSE Enable or disable automatically - running migrations. -**migration_type** 'timestamp' 'timestamp' / 'sequential' The type of numeric identifier used to name - migration files. -========================== ====================== ========================== ============================================= - -*************** -Class Reference -*************** - -.. php:class:: CI_Migration - - .. php:method:: current() - - :returns: TRUE if no migrations are found, current version string on success, FALSE on failure - :rtype: mixed - - Migrates up to the current version (whatever is set for - ``$config['migration_version']`` in *application/config/migration.php*). - - .. php:method:: error_string() - - :returns: Error messages - :rtype: string - - This returns a string of errors that were detected while performing a migration. - - .. php:method:: find_migrations() - - :returns: An array of migration files - :rtype: array - - An array of migration filenames are returned that are found in the **migration_path** property. - - .. php:method:: latest() - - :returns: Current version string on success, FALSE on failure - :rtype: mixed - - This works much the same way as ``current()`` but instead of looking for - the ``$config['migration_version']`` the Migration class will use the very - newest migration found in the filesystem. - - .. php:method:: version($target_version) - - :param mixed $target_version: Migration version to process - :returns: TRUE if no migrations are found, current version string on success, FALSE on failure - :rtype: mixed - - Version can be used to roll back changes or step forwards programmatically to - specific versions. It works just like ``current()`` but ignores ``$config['migration_version']``. - :: - - $this->migration->version(5); |