更新产品表时出现此问题。它显示了错误消息，但我无法确定问题出在哪里，因为它的自定义消息。我只需要更新产品时，用户作出了改变，并通知如果用户没有作出改变。
产品更新\查看.php

<div class="col-sm-10" id="main" style="padding: 20px;">
    <?php
    echo form_open("item/item_update/$item->prod_id");
    echo form_fieldset('<h3 class="text-info">Update Item</h3>');
    ?>
    <input type="hidden" name="cur_code" value="<?php echo $item->prod_code ?>">
    <input type="hidden" name="cur_name" value="<?php echo $item->prod_desc ?>">
    <input type="hidden" name="cur_category" value="<?php echo $item->category_name ?>">
    <input type="hidden" name="cur_brand" value="<?php echo $item->brand_name ?>">
    <input type="hidden" name="cur_sizes" value="<?php echo $item->size ?>">
    <input type="hidden" name="cur_price" value="<?php echo $item->original_price ?>">

    <div class="form-group">
        <label for='prod_code'>Product Code:</label>
        <input type="text" name="up_code" class="form-control" value="<?php echo $item->prod_code; ?>">
    </div>
    <div class="form-group">
        <label for='prod_name'>Product Description:</label>
        <input type="text" name=up_name" class="form-control" value="<?php echo $item->prod_desc; ?>">
    </div>
    <div class="form-group">
        <label for='up_brand'>Brand:</label>
        <select name="up_brand" class="form-control">
            <option value="Select Brand" selected="selected">Select Brand</option>

            <?php foreach($brand as $br): ?>
                <option value="<?php echo $br->brand_id; ?>" <?php
                if($br->brand_id == $item->brand_id)
                {
                    echo "selected='selected'";
                }
                ?>><?php echo $br->brand_name ?></option>
<?php endforeach; ?>
        </select>
    </div>      

    <div class="form-group">
        <label for="category">Category</label>
        <select class="form-control" name="up_category" id="category">
            <option value="Select Brand"> Select Category</option>
            <?php foreach($category as $cat): ?>
                <option value="<?php echo $cat->category_id; ?>" <?php
                        if($cat->category_id == $item->category_id)
                        {
                            echo "selected='selected'";
                        }
                        ?>><?php echo $cat->category_name; ?></option>
<?php endforeach; ?>
        </select>
    </div>
    <div class="form-group">
        <label for="sizes">Size:</label>
        <select class="form-control" name="up_sizes" id="sizes" disabled="disabled">

                    <?php foreach($sizes as $sz): ?>
                <option value="<?php echo $sz->size_id; ?>" <?php
                    if($sz->size_id == $item->size_id)
                    {
                        echo "selected='selected'";
                    }
                    ?>><?php echo $sz->size; ?></option>
<?php endforeach; ?>
        </select>
    </div>

    <div class="form-group">
        <label for='prod_price'>Price:</label>
        <input type="text" name="up_price" class="form-control" value="<?php echo $item->original_price; ?>">
    </div>

    <div class="form-group">
        <input type="submit" name="submit_account" class="btn btn-primary" value="Update Product" >
    </div>
</div>

<script src="<?php echo base_url() ?>dropdown/js/jquery.js"></script>
<script src="<?php echo base_url() ?>dropdown/js/bootstrap.min.js"></script>
<script type="text/javascript">
    $(document).ready(function () {
        $('#category').on('click', function () {
            var category_id = $(this).val();
            if (category_id === '')
            {
                $('#sizes').prop('disabled', true);
            } else
            {
                $('#sizes').prop('disabled', false);
                $.ajax({
                    url: "<?php echo base_url() ?>welcome/get_sizes",
                    type: "POST",
                    data: {'category_id': category_id},
                    dataType: 'json',
                    success: function (data) {
                        $('#sizes').html(data);
                    },
                    error: function () {
                        alert('Error occur...!!');
                    }
                });
            }
        });

    });

</script>
</div>

<?php echo form_close(); ?>

控制器

public function item_update($id)
{
    $this->load->model('item_model');
    $this->form_validation->set_rules('up_code', 'Product Code', 'required');
    $this->form_validation->set_rules('up_name', 'Product Description', 'required');
    $this->form_validation->set_rules('up_price', 'Price', 'required');

    $cur_name = $this->input->post('cur_name');
    $cur_code = $this->input->post('cur_code');
    $cur_category = $this->input->post('cur_category');
    $cur_price = $this->input->post('cur_price');
    $cur_brand = $this->input->post('cur_brand');
    $cur_sizes = $this->input->post('cur_sizes');
    $up_name = $this->input->post('up_name');
    $up_category = $this->input->post('up_category');
    $up_code = $this->input->post('up_code');
    $up_price = $this->input->post('up_price');
    $up_sizes = $this->input->post('up_sizes');
    $up_brand = $this->input->post('up_brand');
    if($cur_code === $up_code && $cur_name === $up_name && $cur_brand === $up_brand && $cur_category === $up_category && $cur_sizes === $up_sizes && $cur_price === $up_price)
    {
        $this->session->set_flashdata('successMessage', '<div class="alert alert-info">No Changes</div>');
        redirect(base_url('home'));
    }
    else
    {
        if($this->form_validation->run() == FALSE)
        {
            $this->session->set_flashdata('errorMessage',
              '<div class="alert alert-danger">Opss Something Went Wrong Updating The Item. Please Try Again.</div>');
            redirect(base_url('home'));
        }
        else
        {
            $this->load->model('item_model');
            $update = $this->item_model->update_item($id, $up_code, $up_name, $up_brand, $up_category, $up_size,
              $up_price);

            if($update)
            {
                $this->session->set_flashdata('successMessage',
                  '<div class="alert alert-success">Item Updated</div>');
                redirect(base_url('home'));
            }
        }
    }
}

还有我的模特

public function update_item($id, $up_code, $up_name, $up_brand, $up_category,
  $up_sizes, $up_price)
{
    $this->load->database();
    $data = array(
      'prod_code' => "$up_code",
      'prod_desc' => "$up_name",
      'brand_id' => "$up_brand",
      'category_id' => "$up_category",
      'size_id' => "$up_sizes",
      'original_price' => "$up_price",
    );

    $this->db->where('id', $id);
    return $this->db->update('products', $data);
}

它只显示消息“opss something going wrong update the item”。请再试一次“