unl_multisite.install

<?php

use Drupal\Core\Database\Database;

function unl_multisite_schema() {
  $schema = array();
  $schema['unl_sites'] = array(
    'description' => 'Multisite installations.',
    'fields' => array(
      'site_id' => array(
        'type'     => 'serial',
        'unsigned' => TRUE,
        'not null' => TRUE,
      ),
      'd7_site_id' => array(
        'type'     => 'varchar',
        'length'   => 255,
        'default'  => null,
      ),
      'site_path' => array(
        'type'     => 'varchar',
        'length'   => 255,
        'not null' => TRUE,
        'default'  => '',
      ),
      'uri' => array(
        'type'     => 'varchar',
        'length'   => 255,
        'not null' => TRUE,
        'default'  => '',
      ),
      'installed' => array(
        'type'     => 'int',
        'not null' => TRUE,
        'default'  => 0,
      ),
    ),
    'primary key' => array('site_id'),
    'unique keys' => array(
      'site_path' => array('site_path'),
      'uri' => array('uri'),
    ),
  );

  $schema['unl_sites_aliases'] = array(
    'description' => 'Table of URL aliases for multisite sites.',
    'fields' => array(
      'site_alias_id' => array(
        'type'     => 'serial',
        'unsigned' => TRUE,
        'not null' => TRUE,
        ),
      'site_id' => array(
        'type'     => 'int',
        'unsigned' => TRUE,
        'not null' => TRUE,
      ),
      'base_uri' => array(
        'type'     => 'varchar',
        'length'   => 255,
        'not null' => TRUE,
      ),
      'path' => array(
        'type'     => 'varchar',
        'length'   => 255,
        'not null' => TRUE,
      ),
      'installed' => array(
        'type'     => 'int',
        'not null' => TRUE,
        'default'  => 0,
      ),
    ),
    'primary key' => array('site_alias_id'),
    'unique keys' => array(
      'alias_uri' => array('base_uri', 'path'),
    ),
    'foreign keys' => array(
      'aliased_site' => array(
        'table' => 'unl_sites',
        'columns' => array('site_id' => 'site_id'),
      ),
    ),
  );

  return $schema;
}

/**
 * Adds the 'd7_site_id' and 'd7_site_path' fields to the unl_sites table.
 */
function unl_multisite_update_8001() {
  $d7_site_id = [
    'type' => 'varchar',
    'length' => 255,
    'not null' => FALSE,
    'default' => NULL,
  ];
  $d7_site_path = [
    'type' => 'varchar',
    'length' => 255,
    'not null' => FALSE,
    'default' => NULL,
  ];

  $schema = Database::getConnection()->schema();
  $schema->addField('unl_sites', 'd7_site_id', $d7_site_id);
  $schema->addField('unl_sites', 'd7_site_path', $d7_site_path);
}

/**
 * Implements hook_update_N().
 * Remove 'd7_site_path' field from 'unl_sites' table
 */
function unl_multisite_update_8002() {
    $schema = \Drupal::database()->schema();
    $table_name = 'unl_sites';
    $field_name = 'd7_site_path';

    // Check if the field exists before attempting to drop it.
    if ($schema->fieldExists($table_name, $field_name)) {
      // Drop the field.
      $schema->dropField($table_name, $field_name);
      \Drupal::messenger()->addMessage(t('Field @field has been successfully removed from @table.', [
        '@field' => $field_name,
        '@table' => $table_name,
      ]));
    }
    else {
      \Drupal::messenger()->addMessage(t('Field @field does not exist in @table.', [
        '@field' => $field_name,
        '@table' => $table_name,
      ]), 'warning');
    }
  }