从大型表格发布数据并在错误后保留输入数据的最佳方式

This is a "best practice"/"most efficient" question. I have a large form (20+ fields). Form post into one large MySQL table.

No I can't break up the form and no, I can't break up the table (its being used to hold measurements); used by admin sales reps. Also, I don't want to use Javascript.

I know I can do this: HTML

<form action="etc.php" method="post">    
<input type="text" name="neck" value="">
<input type="text" name="arm" value="">
<input type="text" name="back" value="">
<input type="text" name="chest" value="">
<input type="text" name="legs" value="">
<submit button>

PHP

<? 
$_POST['neck']; 
$_POST['back']; 
$_POST['arm']; 
$_POST['chest']; 
$_POST['legs']; 
$postMeasurements = "INSERT INTO measurements (etc, etc, etc,) VALUES (etc, etc, etc) WHERE etc='etc'; query ($postMeasurements);
?>

But is there a faster way? Instead of having to declare each individual post, simply just run a loop that takes all the data post and inserts into the table. Even if the data has be in the same order of the columns of the table or if the input names have to be the same as the table column names is fine by me; I am just getting tired have to keep writing all these $_POST variables into.

Second question: What is the best way to hold this data in case of an error? As it stands now, I hold everything in $_SESSION (one session variable for each input), then redirect back to the form page if there is an error with an error message. then echo each $_SESSION variables as that inputs value.

Thanks,

if the fields as the exact names as the field names. post can only have the fields and nothing else

 //if $_POST has the form then, also this is very unsafe because there is no injection prevention too

 $sql = "INSERT INTO table (" . implode(",", array_keys($_POST)) . ")"
      . "VALUES ('" . implode("','", array_values($_POST)) . "')";

You can directly use $_POST['foo'] inside your query, and need not declare :) .

holding the data could be in session, or inline cache, if you have huge data, its better to use some cache in server, and onload of the form, it retrieves the data from server based on SESSION_ID

Have the page post to itself.

Then do something like this:

if($_SERVER["REQUEST_METHOD"] == "POST"){
    // validate and insert post data
    header("Location: $successUrl");
    exit();
}
?>
<form action="etc.php" method="post">    
    <input type="text" name="neck" value="<?= $_POST["neck"]?>">
    <input type="text" name="arm" value="<?= $_POST["arm"] ?>">
    ....