Question

I have an sql table with articles in it. I stored the order of the articles in an INT field in sql.
With an ajax post from the (drag and drop) UI, i got an array with integers (new order).
example:
Old order: 2,1,3,4
New order should be: 2,1,4,3
php:

$i = 1;    
foreach ($inputarray as $var) :
        if ($i != $var) :
            $this->_sqli->query("UPDATE articles 
    SET artorder=$i WHERE artorder = $var and pagesid = $pagesid");
        endif;

    $i++;
endforeach;

The problem: when i try to swap elements, they are gonna be the same. So the previous example’s output will be: 2,1,4,4
How should i update my sql?

Answer 1

This will not work as long as “artorder” is the unique key that you use when updating a row. This is because you will run into situations where the artorder is the same in two rows; thus, you no longer have a unique key. Just add a primary key to the table and use that on your UPDATE statements:

ALTER TABLE articles ADD articleId INT(5) NOT NULL,
ADD PRIMARY KEY (articleId)