如何在PHP上使用AJAX检索MySQL值？

Question

Ok, this one is taking me some time now, I've read other topics and cannot seem to solve it.

I have a select populated with a PHP function article_search() that retrieves all article names from a the table article in my DB

<select id="article_select">
    <?php
        $article_group = article_search();
        foreach($article_group as $item) {
            echo "<option value=\"{$item["idArt"]}\">{$item["name"]}</option>";
        }
    ?>  
</select>

What I need is, when the user selects an article, an AJAX function search the field price from the table article in the database and puts the result in this element:

<p>Price:
    <input type="text" class="details" id="price" name="price">
</p>

Needless to say that I have no experience in AJAX, but it seems like the only solution at these point.

Every bit of help would be appreciated.

Answer 1

Personally, I would put the price in the the original options:

<select id="article_select">
    <?php
        $article_group = article_search();
        foreach($article_group as $item) {
            echo "<option value=\"{$item["idArt"]}\" price=\"{$item['price']}\">{$item["name"]}</option>";
        }
    ?>  
</select>

Then, you can collect this using JQuery like so (http://jsfiddle.net/Twisty/6unsdztu/):

$(document).ready(function(){
    $("#article_select").change(function(){
        var price = $(this).find("option:selected").attr("price");
        var $inp = $('<input />',{
            type: "text",
            class: "details",
            id: "price_" + $(this).val(),
            name: "price",
            value: price
        });
        var $p = $('<p />');
        $p.append("<label>Price:</label>", $inp);
        $p.appendTo("#price_form");
    });
});

This seems like a bad idea overall. The user could try to manipulate the price if you're passing it back to the Database, unless they get a chance to negotiate the price.

Since the Price is in the DB, why bring it out to a text field? he end, if this is a shopping cart, we just need to know which items are in the cart, and we can calculate a total later or as we go. Hopefully the above example fits what you need. If not, comment or edit your post with more details.