Question

为什么最后一个＆＃39; In Stock＆＃39;字段替换所有其他＆＃39;库存＆＃39;当我试图对数量施加价值时，哪个领域？

<form action="add_sales.php" method="POST">
    <table class="table table-striped table-bordered table-hover results table-fixed">
        <thead>
            <tr>
                <th class="text-center">#</th>
                <th>Product Name</th>
                <th>Description</th>
                <th>Price</th>
                <th>In Stock</th>
                <th style="width: 20%">Quantity</th>
            </tr>
            <tr class="warning no-result">
                <td colspan="8"><i class="fa fa-warning"></i> No Product Found</td>
            </tr>
        </thead> 
        <tbody>
            <?php 
                $query = "SELECT * FROM products";
                $exec = mysqli_query($connection, $query);
                $a = 1;
                $b = 1;
                while ($row = mysqli_fetch_array($exec)) {
                    $product_id = $row['product_id'];
                    $product_name = $row['product_name'];
                    $product_price = $row['sell_price'];
                    $description = $row['description'];
                    $product_quantity = $row['quantity'];
                }
            ?>
            <tr>
                <td class="text-center"><?php echo $product_id; ?><input type="hidden" name="product_id[]" value="<?php echo $product_id; ?>"></td>
                <td><?php echo $product_name; ?></td>
                <td><?php echo $description; ?></td>
                <td><?php echo $product_price; ?></td>
                <td><input type="number" name="hehe" value="<?php echo $product_quantity; ?>" id="<?php echo "qtyResult" . $a++; ?>" disabled></td>
                <td><input type="number" name="qtyBuy[]" id="<?php echo "qtyBuy" . $b++; ?>" onkeyup="updateStock(this, event)"></td>
            </tr>
            <?php } ?>
        </tbody>
    </table>  
    <div class="form-group">
        <input type="submit" name="addCart" value="Add Items to Cart" class="btn btn-info pull-right">
    </div>
</form>

这是我的jQuery脚本。我认为问题出在var inStock的价值中。当我将var inStock的值更改为固定数字时，它的工作正常。

function updateStock(obj, event) {
    var inputQty = obj.value;
    var inStock = "<?php echo $product_quantity; ?>";
    $(obj).closest('tr').find('input[id^="qtyResult"]').val(inStock - inputQty);
}

Answer 1

因为$product_quantity将被设置为循环中的最后一个值。

如果您查看源代码并查看javascript函数，您会看到它：

function updateStock(obj, event) {
    var inputQty = obj.value;
    var inStock = "234"; //or whatever the last value was
    $(obj).closest('tr').find('input[id^="qtyResult"]').val(inStock - inputQty);
}

由于页面加载后值可能会发生变化（因此在php退出后），你应该在需要时从dom中获取当前值：

function updateStock(obj, event) {
    var inputQty = obj.value;
    var quantityInput = $(obj).closest('tr').find('input[id^="qtyResult"]');
    quantityInput.val(quantityInput.val() - inputQty);
}

使用jQuery选择附加ID属性

1 个答案: