Drupal 8: Create a new table in database using hook_update_N()

hook_update_N.php

<?php


/**
 *The numbers are normally composed of three parts:
 * - 1 or 2 digits for Drupal core compatibility (Drupal 8, 9, 10, etc.). This
 *   convention must be followed.
 * - 1 digit for your module's major release version; for example, for 8.x-1.*
 *   use 1, for 8.x-2.* use 2, for Core 8.0.x use 0, and for Core 8.1.x use 1.
 *   This convention is optional but suggested for clarity.
 * - 2 digits for sequential counting, starting with 01. Note that the x000
 *   number can never be used: the lowest update number that will be recognized
 *   and run for major version x is x001.
 * Examples:
 * - node_update_8001(): The first update for the Drupal 8.0.x version of the
 *   Drupal Core node module.
 * - mymodule_update_8101(): The first update for your custom or contributed
 *   module's 8.x-1.x versions.
 * - mymodule_update_8201(): The first update for the 8.x-2.x versions.
 */
 
/**
 * Adds new table "my_table".
 */
function MY_MODULE_update_8001() {
  $database = \Drupal::database();
  $schema = $database->schema();

  $table_name = 'my_table';
  $table_schema = [
    'fields' => [
      'sid' => [
        'type' => 'serial',
        'size' => 'big',
        'not null' => TRUE,
      ],
      'nid' => [
        'type' => 'int',
        'not null' => TRUE,
      ],
      'action' => [
        'type' => 'varchar',
        'not null' => TRUE,
        'length' => 25,
      ],
      'uids' => [
        'type' => 'blob',
        'not null' => TRUE,
      ],

    ],
    'primary key' => ['sid'],
  ];

  $schema->createTable($table_name, $table_schema);

}