代码如下：

<?php

/*
  Plugin Name: MyPluggin
  Plugin URI: http://localhost/
  Description: 
  Version: 0.0.2
  Author: localhost
  Author URI: http://localhost/
  License: GPL2
 */


function crear_tablas() {

    global $wpdb;


    require_once(ABSPATH . \'wp-admin/includes/upgrade.php\');


    $table_name_1 = $wpdb->prefix . "usuarios";
    $consulta_1 = "create table $table_name_1(
                count bigint unsigned not null  primary key auto_increment,
                ID bigint not null references wp_users(ID),
                puntosDisponibles bigint unsigned default 1000
            );";

    dbDelta($consulta_1);


    $table_name_2 = $wpdb->prefix . "deportes";
    $consulta_2 = "create table $table_name_2(
                ID int unsigned not null  primary key auto_increment,
                nombre tinytext
            );";

    dbDelta($consulta_2);

    $table_name_3 = $wpdb->prefix . "ligas";
    $consulta_3 = "create table $table_name_3(
    ID int unsigned not null  primary key auto_increment,
    nombre tinytext
);";

        dbDelta($consulta_3);


    $table_name_4 = $wpdb->prefix . "equipos";
    $consulta_4 = "create table $table_name_4(
    ID int unsigned not null  primary key auto_increment,
    nombre tinytext,
    apodo  tinytext,
    deporte int unsigned not null references deportes(id),
    liga    int unsigned not null references ligas(id)

);";

        dbDelta($consulta_4);

        $table_name_5 = $wpdb->prefix . "eventos";
    $consulta_5 = "create table $table_name_5(
    count bigint unsigned not null  primary key auto_increment,
    ID  bigint unsigned not null references wp_posts(ID),
    localID int unsigned not null references equipos(ID),    
    visitanteID int unsigned not null references equipos(ID),
    goleslocal  int unsigned,
    golesVisitante  int unsigned,
    fecha DATE not null,
    hora  TIME not null,     
    status  int unsigned default 0

);";

        dbDelta($consulta_5);

    $table_name_6 = $wpdb->prefix . "apuestas";
    $consulta_6 = "create table $table_name_6(
    count bigint unsigned not null  primary key auto_increment,
    eventoID bigint unsigned not null references   wp_posts(ID),
    puntosJugados   bigint unsigned not null,
    userID  bigint unsigned not null references wp_users(ID), 
    fecha DATE not null,
    hora  TIME not null,     
    resultado int unsigned not null,
    porcentaje float(4,2),
    estado int unsigned not null default 0
);";

        dbDelta($consulta_6);

}






function instalar_sistema_apuestas () {
    crear_tablas();
    //crearCategorias();
    //crearPaginaPerfil();

 }

register_activation_hook(__FILE__,\'instalar_sistema_apuestas\');







?>

mysql> show tables;
+------------------------+
| Tables_in_wordpress |
+------------------------+
| wp_commentmeta         |
| wp_comments            |
| wp_links               |
| wp_options             |
| wp_postmeta            |
| wp_posts               |
| wp_term_relationships  |
| wp_term_taxonomy       |
| wp_terms               |
| wp_usermeta            |
| wp_users               |
+------------------------+
11 rows in set (0.00 sec)