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Basically, a user is filling in a form to enter a product, and then stating this product is 'specifically' for a user by ticking checkboxes for those users.

Product Name: foo

Specific Users:

  • Bob
  • Bill
  • Ben
  • Rob

So the user can 'check' 1 or more of the users to link the product with.

I have set-up database tables:

USER | userID | name |

PRODUCTS | productID | name |

LINKTABLE | linkID | productID | userID |

What I'd like to happen is when the user checks 'Bill' and 'Ben' and clicks 'Submit', the product is added to the product table, the new productID is returned, a loop happens on an INSERT script to add a new record into the LINKTABLE with the productID and userID for each of the checked users.

So far I've got to the bit of inserting the product details and returning the productID, but I'm struggling with the loop to insert the productID and userID into the link table.

$product = $_POST["product"];

$sql = "INSERT INTO products ('name') VALUES ($product);
$result = mysql_query($sql);

$newProductID = mysql_insert_id();

I tried this:

if(!empty($_POST['users'])) {
foreach($_POST['users'] as $userID)
    {
        $sql = "INSERT INTO linktable (productID, userID) VALUES (".$newProductID.", ".$userID.")";
        $result = mysql_query($sql) or die(mysql_error()."<br />".$sql);
    }

But that threw an error of:

Warning: Invalid argument supplied for foreach() in ....

On the line of the 'foreaach' loop.

Any help would be great. Thanks!

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1  
For future users seeing your questions. If you know this, great! Please, don't use mysql_* functions in new code. They are no longer maintained and the deprecation process has begun on it. See the red box? Learn about prepared statements instead, and use PDO or MySQLi - this article will help you decide which. If you choose PDO, here is a good tutorial. – Jeremy1026 Feb 6 at 16:31

3 Answers

up vote 0 down vote accepted

I suspect that $_POST['users'] isn't an array. What does your checkboxes look like in your html? They need to look like this:

<input type="checkbox" name="users[]" value="Bob">Bob
<input type="checkbox" name="users[]" value="Bill">Bill
<input type="checkbox" name="users[]" value="Ben">Ben

Notice the name users[]

Now you can do:

foreach ($_POST['users'] as $user) {
    // do something
}
share|improve this answer
Ah yeah this worked. I just hadn't added the [] to the name in the HTML. Thanks a lot Sean. – user1996869 Feb 6 at 16:44
No problem. Happy to help! – SeanWM Feb 6 at 16:48
up vote 0 down vote

$_POST['users'] is going to be a string no? I haven't done PHP in a while, but you can't POST an array or anything, only a string. So your can't foreach over a string.

What type of data is $_POST['users']? Is it a list. I am more familiar with Coldfusion where you can loop over a list using different syntax, but I am pretty sure you'll have to check the data of your post variable and act on it accordingly.

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Cheers for the quick response. $_POST['users'] is coming from the checkbox name <input type="checkbox" name="resellers" id=$id>Bob<br /> <input type="checkbox" name="resellers" id=$id>Ben<br /> etc – user1996869 Feb 6 at 16:34
up vote 0 down vote

If you want to use:

foreach($_POST['users'] as $userId)

Then you need a checkbox array in the HTML, and set the value attribute to the ID, like so:

Bob <input type="checkbox" name="users[]" value="101" />
Bill <input type="checkbox" name="users[]" value="102" />
Ben <input type="checkbox" name="users[]" value="103" />

Note the use of [] in the name, which makes it an array.

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