Looping Through Checkboxes while Inside Another Loop

Question

I'm having some trouble solving a nested loop. I have a form that sends a series of data to the mysql database. I use a while function and it works correctly. But now I have an checkbox option for each entry, and that's my problem.

The checkbox should be sent to another table, with the id, the series ID and a checkbox per row. But all I can do is make the answer from the first series repeat through the others.

This is what I want:

Lance 1
 Checkbox 1
 checkbox 3
 checkbox 4
Lance 2
 checkbox 2
 checkbox 3
Lance 3
 checkbox 1
 checkbox 2
 checkbox 3

This is what I get
Lance 1
 Checkbox 1
 checkbox 3
 checkbox 4
Lance 2
 Checkbox 1
 checkbox 3
 checkbox 4
Lance 3
 Checkbox 1
 checkbox 3
 checkbox 4

My loop code so far:

$i=0;
$elements = count($lance);
while ($i < $elementss) {
$query = "INSERT INTO 
    mapa_bordo_lance 
        (id_mb, lance, data_lance, lat, lon, anzol, isca, hora_lan, hora_rec, ave_capt, mm_uso)
    VALUES 
        ('$id_mb', '$lance[$i]', '$data_lance[$i]', '$lat[$i]', '$lon[$i]', '$anzol[$i]', '$isca[$i]', '$hora_lan[$i]', '$hora_rec[$i]',
        '$ave_capt[$i]', '$mm_uso[$i]')";
$result = mysql_query($query, $link);

$y = 0;
$elementss2 = count($checkbox);
while ( $y < $elements2) {
    $query = "INSERT INTO mapa_bordo_mm (id_mb, lance, mm)
            VALUES ('$id_mb', '$lance[$y]', '$medida_metiga[$y]')";
    $result = mysql_query($query, $link);

$y++;
}
$i++;
}

Answer 1

About the Checkboxes

According to the information presented in your question, comments, and pasted snippets, I have the feeling that you are getting the same Checkbox values for each Lance because in this code:

$y = 0;
$elementss2 = count($checkbox);
    while ( $y < $elements2) {
    $query = "INSERT INTO mapa_bordo_mm (id_mb, lance, mm)
              VALUES ('$id_mb', '$lance[$y]', '$medida_metiga[$y]')";
    $result = mysql_query($query, $link);
    $y++;
}

it appears that the $medida_metiga[$y] part is only calling the same $medida_metiga (and its array items...) rather than calling the next $medida_metiga0 and $medida_metiga1 parts in your example array (given in this link.)

You may need to find a way to concatenate your $medida_metiga array/key with a number (like 0, 1, ... etc.) kind of like this:$medida_metiga[$y.$some_number_here] in order to find the matching checkboxes. But you may also want to rethink the naming for the $medida_metiga, $medida_metiga0, $medida_metiga1 approach.

For example, instead of:

$medida_metiga

What if you began with:

$medida_metiga0

This would allow you to more easily iterate through the array/keys without having to check if this item has a number at the end or not.

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About the SQL

When you have a chance, it would probably be a good idea to check out how to use prepared statements in PHP if for no other reason than to prevent SQL injection. This other answer may give you some tips on getting started with prepared statements.

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About the Looping

While while loops can technically work for your purposes, it might be worth using either for or foreach loops in this case, as those sorts of loops can help keep code clean and improve code readability. It might be worth taking a look at this other answer for tips on selecting loops for different applications.

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About the Variable Naming

You may have already seen this, but do make sure that your variable names ($elements or $elementss?) match:

$elements = count($lance);
while ($i < $elementss) { ... }

// ...

$elementss2 = count($checkbox);
while ( $y < $elements2) {