PDO / mySQL How to bind multiple values to store multiple rows - php

Question

To store 6 invoce items from a website through a form method="post", I use several input elements like this
<input name="item[]" value="6 hour service"/>
<input name="item[]" value="1 days travel"/>
....
Serverside I copy $_POST['Item'] to an array like this
item[]= $_POST['Item'];
Then I can access item[] and it looks like this
[item] => Array
(
[0] => 6 hour service
[1] => 1 days travel
[2] => ....
)
Then this SQL statement follows
try {
$obj = $this->dbcon->prepare('INSERT INTO invoice_item
( ID, item)
VALUES(:ID,:item)');
for ($i=0;$i<6;$i++) {
if (!empty($item[0][$i])) {
$obj->bindValue(':ID', $this->dbcon->lastInsertId(), PDO::PARAM_INT);
$obj->bindValue(':item', $item[0][$i], PDO::PARAM_STR);
$succ = $obj->execute();
}
}
}
catch(PDOException $e) {
echo "Error: " . $e->getMessage();
}
This works fine for a fix amount of items.
But what is the correct way to access $_POST, bind it and to store it when the amount of items are not known ?
EDIT :
How to iterate over $_POST["Item"] directly ?

Answer 1

Check if $i is less than the number of items rather than less than a fixed value.
for ($i=0;$i<count($item[0]);$i++) {
if (!empty($item[0][$i])) {
alternatively you could use foreach:
foreach ($item[0] as $value) {
if (!empty($value)) {

Answer 2

First of all, you don't need to necessarily bind the ID, because it become from the db itself. Then, you can use an unique query.
Get the ID:
$id = $this->dbcon->lastInsertId();
Filter $_POST['Item'] to discard empty values:
$items = array_values( array_filter( $_POST['Item'] ) );
Create a string with your query:
$query = substr( "INSERT INTO invoice_item (ID, item) VALUES " . str_repeat( "($id, ?),", count($items) ), 0, -1);
Assuming a $_POST['Items'] with three not-empty values and id = 3, now $query is:
INSERT INTO invoice_item (ID, item) VALUES (3, ?),(3, ?),(3, ?)
Now you can prepare the query and executing it binding all parameters at once (using an array as ->execute argument, parameters are bind as strings):
$obj = $this->dbcon->prepare( $query );
$obj->execute( $items );