What are Setup Scripts in Magento 2 and Why You Should Use Them

So you have created your first Magento 2 module.

You have created the registration.php, the module.xml, everything. You have taken good care to see that your code quality is good and you have put comments for every single class and function you’ve developed. Sounds like a perfect module right? One small catch.

Your module requires a table to be created in the database, let’s say “my_first_module_table”. And it has four columns.

• 
  
  id – int (primary key)
  name – varchar(100)
  description – varchar(255)
  created_at – timestamp (default – CURRENT_TIMESTAMP)
  
  
• id – int (primary key)
• name – varchar(100)
• description – varchar(255)
• created_at – timestamp (default – CURRENT_TIMESTAMP)

Now, whoever downloads your module, and installs it into their Magento installation, has to create that table, having the exact same schema, for your module to work properly. Seems kind of a headache right? So what do you do?

Don’t worry. You don’t have to go to every single client of yours to run the “CREATE TABLE” mySQL command at their system. Magento has provided a way for the modules that you create to modify the schema of the Magento database.

Setup Scripts

Setup scripts are certain classes inside your module which are executed, either once, or whenever your module version is updated. Setup scripts in Magento 2 database configuration files that modify the Magento installation. They are usually used for database configuration but can be used for many other things.Magento supports 4 kinds of setup scripts

InstallSchema 

Run once per module. Used to add new tables or modify existing table architecture in the database. Implements the Magento\Framework\Setup\InstallSchemaInterface

InstallData

 Run once per module. Used to add/edit/delete records (rows) from existing tables in the database. Implements the Magento\Framework\Setup\InstallDataInterface.

UpgradeSchema

Runs every time the module version changes. Used to add new tables or modify existing table architecture in the database. Implements the Magento\Framework\Setup\UpgradeSchemaInterface.

UpgradeData

Runs every time the module version changes. Used to add/edit/delete records (rows) from existing tables in the database. Implements the Magento\Framework\Setup\UpgradeDataInterface.

So coming back to our above example, we could probably create an InstallSchemain our module, and create our table in that class.

<?php
/**
*
* @package magento2
* @author Jayanka Ghosh
* @license

https://opensource.org/licenses/OSL-3.0

Open Software License v. 3.0 (OSL-3.0)
* @link

https://www.codilar.com/

*/

namespace Jayanka\HelloWorld\Setup;


use Magento\Framework\DB\Ddl\Table;
use Magento\Framework\Setup\InstallSchemaInterface;
use Magento\Framework\Setup\ModuleContextInterface;
use Magento\Framework\Setup\SchemaSetupInterface;

class InstallSchema implements InstallSchemaInterface
{

/**
* Installs DB schema for a module
*
* @param SchemaSetupInterface $setup
* @param ModuleContextInterface $context
* @return void
*/
public function install(SchemaSetupInterface $setup, ModuleContextInterface $context)
{
$this->createMyTable($setup);
}

protected function createMyTable(SchemaSetupInterface $setup) {
$tableName = $setup->getTable("my_first_module_table");
$table = $setup->getConnection()->newTable(
$tableName
)->addColumn(
'id',
Table::TYPE_INTEGER,
null,
['identity' => true, 'unsigned' => true, 'nullable' => false, 'primary' => true],
'entity_id'
)->addColumn(
'name',
Table::TYPE_TEXT,
100,
['nullable' => false]
)->addColumn(
'description',
Table::TYPE_TEXT,
255,
['nullable' => false]
)->addColumn(
'created_at',
Table::TYPE_TIMESTAMP,
null,
['nullable' => false, 'default' => Table::TIMESTAMP_INIT],
'Create date'
)->setComment(
'My first module table'
);
$setup->getConnection()->createTable($table);
}
}

That’s all on setup scripts. You can use the same concept to create new tables, or update existing tables, or even add data into existing tables (like creating a product attribute which you need in your module).