in effetti diventa scomodo se hai molti dati, io userei le sessioni.
comunque si hai capito cio che suggerivo.
a.php
<form name="a" action="b.php" method="post">
<input type="text" name="1">
<input type="text" name="2">
</form>
b.php
<form name="b" action="c.php" method="post">
<input type="text" name="3">
<input type="text" name="4">
<input type="hidden name="formA" value="{$_POST["1"]};{$_POST["2"]}">
</form>
c.php
<form name="c" action="d.php" method="post">
<input type="text" name="5">
<input type="text" name="6">
<input type="hidden name="formA" value="{$_POST["formA"]}">
<input type="hidden name="formB" value="{$_POST["3"]};{$_POST["4"]}">
</form>
d.php
Codice PHP:
$formA=explode(";",$_POST["formA"]);
$formB=explode(";",$_POST["formB"]);
$query="insert into table values";
$query.="$formA[0],$formA[1],$formB[0],$formB[1],";
$query.="{$_POST["5"]},{$_POST["6"]}";