它是我的代码，请任何人告诉我为什么wordpress没有在数据库中创建表

Question

它是我的代码，请任何人告诉我为什么wordpress不能在我的数据库中创建表：

function xc_create_all_tables(){

    global $wpdb;

    $cod = $wpdb->prefix."cod_system";
    $charset_collate = $wpdb->get_charset_collate();

    $data = "CREATE TABLE  $cod (
        id int NOT NULL AUTO_INCREMENT,
        picker_name varchar (255) NOT NULL,
        picker_add varchar (255) NOT NULL,
        picker_cell varchar (255) NOT NULL,
        picker_area varchar (255) NOT NULL,
        name varchar (255) NOT NULL,
        addd varchar (255) NOT NULL,
        cell varchar (255) NOT NULL,
        area varchar (255) NOT NULL,
        weight varchar (255) NOT NULL,
        pd_number varchar (255) NOT NULL,
        amount varchar (255) NOT NULL,
        status varchar (255) NOT NULL,
        PRIMARY KEY  (id)
    ) $charset_collate;";

    require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );
    dbDelta( $data );

    $singlecod = $wpdb->prefix."singlecod_system";
    $charset_collate2 = $wpdb->get_charset_collate();

    $data2 = "CREATE TABLE  $singlecod (
        id int NOT NULL AUTO_INCREMENT,
        picker_name varchar (255) NOT NULL,
        picker_add varchar (255) NOT NULL,
        picker_cell varchar (255) NOT NULL,
        picker_area varchar (255) NOT NULL,
        name varchar (255) NOT NULL,
        addd varchar (255) NOT NULL,
        cell varchar (255) NOT NULL,
        area varchar (255) NOT NULL,
        weight varchar (255) NOT NULL,
        pd_number varchar (255) NOT NULL,
        amount varchar (255) NOT NULL,
        status varchar (255) NOT NULL,
        PRIMARY KEY  (id)
    ) $charset_collate2;";

    require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );
    dbDelta( $data2 );

}