如果要在Magento 2中创建新的自定义模块，在某些情况下，您可能需要创建新的数据库表，修改现有的数据库表，并且可能需要在数据库表中设置一些初始缺省值。您可以通过在Magento 2中创建安装/升级脚本来实现此目的。

以下是安装/升级SQL脚本的列表

  • InstallSchema
  • InstallData
  • UpgradeSchema
  • UpgradeData
  • Recurring
  • Uninstall

所有这些类都将位于app/code///Setup文件夹中。

示例文件路径：app/code/Alwayly/CustomScript/Setup

在CLI中运行以下命令时，将运行模块的安装/升级脚本：

php bin/magento setup:upgrade

InstallSchema：

InstallSchema用于更改数据库模式，这意味着创建新数据库表或修改现有数据库表结构。InstallSchema类将在模块安装期间运行。

示例文件路径：app/code/Alwayly/CustomScript/Setup/InstallSchema.php

<?php
 
namespace Alwayly\CustomScript\Setup;
 
use Magento\Framework\Setup\InstallSchemaInterface;
use Magento\Framework\Setup\SchemaSetupInterface;
use Magento\Framework\Setup\ModuleContextInterface;
 
class InstallSchema implements InstallSchemaInterface
{
    public function install(SchemaSetupInterface $setup, ModuleContextInterface $context)
    {
        $installer = $setup;
        $installer->startSetup();
        if (!$installer->tableExists('comments')) {
            $table = $installer->getConnection()
                     ->newTable($installer->getTable('comments'))
                     ->addColumn(
                         'comment_id',
                         \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
                         null,
                         [
                             'identity' => true,
                             'nullable' => false,
                             'primary'  => true,
                             'unsigned' => true,
                         ],
                         'ID'
                     )
                     ->addColumn(
                         'name',
                         \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
                         255,
                         ['nullable => false'],
                         'Name'
                     )
                     ->addColumn(
                         'email',
                         \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
                         255,
                         [],
                         'Email'
                     )
                     ->addColumn(
                         'url_key',
                         \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
                         255,
                         [],
                         'URL Key'
                     )
                     ->addColumn(
                         'message',
                         \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
                         '18K',
                         [],
                         'Message'
                     )
                     ->addColumn(
                         'status',
                         \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
                         1,
                         [],
                         'Comment Status'
                     )
                     ->addColumn(
                         'created_at',
                         \Magento\Framework\DB\Ddl\Table::TYPE_TIMESTAMP,
                         null,
                         ['nullable' => false, 'default' => \Magento\Framework\DB\Ddl\Table::TIMESTAMP_INIT],
                         'Created At'
                     )->addColumn(
                         'updated_at',
                         \Magento\Framework\DB\Ddl\Table::TYPE_TIMESTAMP,
                         null,
                         ['nullable' => false, 'default' => \Magento\Framework\DB\Ddl\Table::TIMESTAMP_INIT_UPDATE],
                         'Updated At')
                     ->setComment('Comments Table');
            $installer->getConnection()->createTable($table);
 
            $installer->getConnection()->addIndex(
                $installer->getTable('comments'),
                $setup->getIdxName(
                    $installer->getTable('comments'),
                    ['name', 'email', 'url_key', 'message'],
                    \Magento\Framework\DB\Adapter\AdapterInterface::INDEX_TYPE_FULLTEXT
                ),
                ['name', 'email', 'url_key', 'message'],
                \Magento\Framework\DB\Adapter\AdapterInterface::INDEX_TYPE_FULLTEXT
            );
        }
        $installer->endSetup();
    }
}

InstallSchema安装程序类文件必须继承\Magento\Framework\Setup\InstallSchemaInterface并且必须具有一个带有2个参数SchemaSetupInterface和ModuleContextInterface的公共方法install（）。

  • SchemaSetupInterface：它是一个设置对象，它提供了与数据库服务器交互的机制。
  • ModuleContextInterface：它有一个名为getVersion（）的方法，用于获取模块的当前版本。

InstallData：

InstallData用于将数据添加到数据库表。InstallData类也将在模块安装期间运行。但它将在InstallSchema类之后运行。

示例文件路径：app/code/Alwayly/CustomScript/Setup/InstallData.php



UpgradeSchema：


UpgradeSchema用于创建或修改现有模块的数据库表。安装脚本和升级脚本之间的主要区别在于，安装脚本将在模块首次安装期间运行。但升级脚本将在每次模块升级时运行。


示例文件路径：app/code/Alwayly/CustomScript/Setup/UpgradeSchema.php


startSetup();
 
        if(version_compare($context->getVersion(), '1.0.1', '<')) {
            $installer->getConnection()->addColumn(
                $installer->getTable( 'comments' ),
                'user_image',
                [
                    'type' => \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
                    'nullable' => true,
                    'length' => '254',
                    'comment' => 'Image',
                    'after' => 'url_key'
                ]
            );
        }
 
        $installer->endSetup();
    }
}



UpgradeSchema安装程序类文件必须继承\Magento\Framework\Setup\UpgradeSchemaInterface，  并且必须具有一个带有2个参数SchemaSetupInterface和ModuleContextInterface的公共方法upgrade（）。


UpgradeData：


UpgradeData用于添加/删除数据库表中的数据。这与UpgradeSchema类相同。


示例文件路径：app/code/Alwayly/CustomScript/Setup/UpgradeData.php


<?php
 
namespace Alwayly\CustomScript\Setup;
 
use Magento\Framework\Setup\UpgradeDataInterface;
use Magento\Framework\Setup\ModuleDataSetupInterface;
use Magento\Framework\Setup\ModuleContextInterface;
 
class UpgradeData implements UpgradeDataInterface
{
 
    protected $_commentFactory;
 
    public function __construct(\Alwayly\CustomScript\Model\CommentFactory $commentFactory)
    {
        $this->_commentFactory = $commentFactory;
    }
 
    public function upgrade(ModuleDataSetupInterface $setup, ModuleContextInterface $context)
    {
        if (version_compare($context->getVersion(), '1.0.1', '<')) {
            $data = [
                'name' => 'Thomus Raj',
                'email' => 'roni_cost@xample.com',
                'url_key' => 'https://www.360magento.com',
                'message' => 'My first comment',
                'status' => 1
            ];
            $post = $this->_commentFactory->create();
            $post->addData($data)->save();
        }
    }
}



Uninstall：


示例文件路径：app/code/Alwayly/CustomScript/Setup/Uninstall.php


<?php
 
namespace Alwayly\CustomScript\Setup;
 
use Magento\Framework\Setup\UninstallInterface;
use Magento\Framework\Setup\SchemaSetupInterface;
use Magento\Framework\Setup\ModuleContextInterface;
 
class Uninstall implements UninstallInterface
{
    public function uninstall(SchemaSetupInterface $setup, ModuleContextInterface $context)
    {
        $installer = $setup;
        $installer->startSetup();
 
        $installer->getConnection()->dropTable($installer->getTable('comments'));
 
        $installer->endSetup();
    }
}



希望这可以帮助你。