PHP - modificar datos

<?php

	require ("conecta.php");

	$pide = $pdo->prepare("SELECT * From paso");

	$pide->execute();

	$dato = $pide->fetchAll(PDO::FETCH_ASSOC);

   foreach($dato as $fila){

		$num = $fila['numemp'];

		$are = $fila['adscrip'];

		$dar = $fila['des_adscri'];

		$pide = $pdo->prepare("UPDATE plantilla SET adscrip = ?, des_adscri = ? WHERE num_emp = ?;");

		$tdan = $pide->execute([$are,$dar,$num]);

	}

?>

$pide = $pdo->prepare("UPDATE plantilla a

	    JOIN paso b

	    on a.num_emp=b.numemp

	    Set a.des_adscri=b.des_adscri");

	$tdan = $pide->execute();