Snippet to create WordPress table with function dbDelta()

create-table.php

global $wpdb;
     $table_name = $wpdb->prefix . 'prueba_tabla';
     $wpdb_collate = $wpdb->collate;
     $sql =
         "CREATE TABLE {$table_name} (
         id mediumint(8) unsigned NOT NULL auto_increment ,
         nombre varchar(255) NULL,
         PRIMARY KEY  (id),
         KEY first (nombre)
         )
         COLLATE {$wpdb_collate}";
 
     require_once(ABSPATH . 'wp-admin/includes/upgrade.php');
     dbDelta( $sql );