将多个复选框值添加到单个行中的多个列

i read other threads but don't think i have found the answer (or maybe just don't know how to implement it...) for this. i have a mysql table with columns for an item size, amongst other things. the user fills in a form in which mulitple sizes may be selected from a series of checkboxes. i want to be able to insert the selected checkbox values in to the proper columns while leaving the other columns either null or if necessary i guess as a 0 value. the columns are tinyint format right now.

'One Size'

<input type="checkbox" name="itemSize[]" value="1" />

Small

<input type="checkbox" name="itemSize[]" value="2" />

Medium

<input type="checkbox" name="itemSize[]" value="3" />

Large

<input type="checkbox" name="itemSize[]" value="4" />

the database table has columns named oneSize, small, medium and large.

HERE IS THE CODE I USED TO TRY TO INSERT A RECORD BASED ON AN ARTICLE IN FOUND IN THE FORUM:

$itemName=$_POST["itemName"];
$allsizes=$_POST["itemSize"];
var_dump($allsizes);
$itemSizing="";
foreach($allsizes as $size){
$itemSizing .=$size .",";
}
$itemSizing=substr($allsizes, 0, -2);
$price=$_POST["price"];
$smallPrice=$_POST["smallPrice"];
$mediumPrice=$_POST["mediumPrice"];
$largePrice=$_POST["largePrice"];
$decsription=$_POST["description"];
$category_id=$_POST["category_id"];

and then in the insert statement i tried listing each column and then the values for the 4 item sizes taken from the checkboxes are listed as the concatenated string:

$SQL="INSERT INTO menuItems (itemName,oneSize,small,medium, large,price,smallPrice,mediumPrice,largePrice,description,category_id) VALUES ('$itemName','$itemSizing','$price','$smallPrice','$mediumPrice','$largePrice','$description','$category_id')";

THIS IS THE ERROR MESSAGE I GOT WHEN ATTEMPTING TO INSERT A RECORD FEATURING A SMALL SIZE AND A LARGE SIZE CHECKED OFF AND THE OTHER TWO CHECKBOXES LEFT UNCHECKED:

array(2) { [0]=> string(1) "2" [1]=> string(1) "4" } 
Warning: substr() expects parameter 1 to be string, array given in menuItems.php on line 162
INSERT INTO menuItems (itemName,oneSize,small,medium,large,price,smallPrice,mediumPrice,largePrice,description,category_id) VALUES ('Garden Salad','','','3.99','','6.99','Fresh greens with lettuce, tomatoes and cucumbers. Served with your choice of dressing.','3') : Error in query. Contact Site Admin

I thought that the string being created was a series of the checkbox values separated out for insertion into the various columns - which is exactly what I want to happen - but clearly it didn't work. I am obviously not very familiar with arrays so I apologize if this is a simple question.

thanks very much for any help anyone can provide...

Since your values are 1-4, you could use a for loop to check if each value is in the POST array and then create your $itemSizing string -

//a size array
$itemSizingArray = array();

//for loop for each size value
for($i=1;$i<=4;$i++){
    //add either a '1' or 'NULL' to the array, based on if the checkbox value is in the array
    $itemSizingArray[] = (in_array($i,$_POST["itemSize"]) ? 1: 'NULL');
}
//implode the array
$itemSizing = implode(', ',$itemSizingArray);

So with your example of Small and Large checked your string would be -

NULL, 1, NULL, 1

The first parameter of substr() needs to be string, you're supplying it with an array as you can see from the output of your var_dump statement:

array(2) { [0]=> string(1) "2" [1]=> string(1) "4" }

As Buse Gönen's comment suggested, join function enables you to convert the array into string with comma delimited values (the array you provided in the example would then be the string "2,4").

$allsizes array no string

example

$itemSizing = join(',',$allsizes);

Remove Code

$itemSizing="";
foreach($allsizes as $size){
    $itemSizing .=$size .",";
}
$itemSizing=substr($allsizes, 0, -2);

2 Typos

Change

$itemSizing=substr($allsizes, 0, -2);

$itemSizing=substr($itemSizing, 0, -1);//-1 to remove trailing ,

Also Change

$decsription=$_POST["description"];

$description=$_POST["description"];