Inserting MULTIPLE Checkboxes into a Database column

Question

I am trying to insert the value of multiple checkboxes if they are checked into one column in my database.

Here is what I have...

if(!empty($_POST['dyuhdb'])) {
    foreach($_POST['dyuhdb'] as $dyuhdb) {
        $dyuhdb . ",";
    }
}

$sql = "INSERT INTO MRF (Q1) VALUES ('". $dyuhdb ."')";

<div class="checkbox">
    <label><input type="checkbox" name="dyuhdb[]" value="1">1</label>
</div>

<div class="checkbox">
    <label><input type="checkbox" name="dyuhdb[]" value="2">2</label>
</div>

<div class="checkbox">
    <label><input type="checkbox" name="dyuhdb[]" value="3">3</label>
</div>

For some reason, if 1 and 2 are ticked, only 2 will enter into my Database?

What am I doing wrong?

It's the first letter of each question in the form, it's a very long form with multiple groups of checkboxes, I have only provided one example as I can duplicate the changes on each. — , May 18 '16 at 14:18
Not a good practise to store checkbox values in a single column. — Nana Partykar, May 18 '16 at 14:22
Putting `$_POST` data directly in your query is a [super bad idea](http://bobby-tables.com/). — tadman, May 18 '16 at 14:55

score 1 · Accepted Answer · edited May 23 '17 at 12:22

The problem is because of the following line,

$dyuhdb . ",";

In each iteration of foreach loop you're overwriting the variable $dyuhdb. Instead simply use implode() function to join the array element with a string(,) and use it in your INSERT query, like this:

if(isset($_POST['dyuhdb']) && count($_POST['dyuhdb'])){
    $checkbox_values = implode(",", $_POST['dyuhdb']);
    $sql = "INSERT INTO MRF (Q1) VALUES ('". $checkbox_values ."')";

    // execute your query
}

Sidenote: Learn about prepared statements because right now your query is susceptible to SQL injection. Also see how you can prevent SQL injection in PHP.

@D.Ashbridge Just one more thing, there's no need to quote your checkbox values, `implode(",", $_POST['dyuhdb'])` will do just fine. I've updated my answer. — Rajdeep Paul, May 18 '16 at 14:26

score 0 · Answer 2 · answered May 18 '16 at 14:17

There will be an extra , in your Query. You could avoid the same by using built in implode function instead of looping post data.

if(!empty($_POST['dyuhdb'])) {
   /* foreach($_POST['dyuhdb'] as $dyuhdb) {
        $dyuhdb . ",";
    }*/

    $dyuhdb = implode(",",$_POST['dyuhdb']);
}

Inserting MULTIPLE Checkboxes into a Database column

2 Answers2