我有一个带有 a 的 Property 模型has_many
和accepts_nested_attributes_for
一个 Image 模型,它使用attachment_fu
. 使用以下代码更新属性会导致每个图像(以及每个图像缩略图)的数据库更新,无论是否对其进行了更改。
properties_controller.rb
def update
@property.update_attributes params[:property]
redirect_to edit_property_path(@property)
end
_form.html.erb
<% form_for @property do |property| %>
...
<ul id='image-admin'>
<% @property.images.each do |image| %>
<li>
<%= image_tag image.public_filename(:front), :alt=> h(image.caption), :size => "218x160" %>
<% property.fields_for :images, image do |img| %>
<%= img.hidden_field :ordering, :class => 'order' %>
<%= img.text_field :caption %>
<span class='img_remove'>
Remove ? <%= img.check_box '_delete' %>
</span>
<% end %>
</li>
<% end %>
</ul>
...
<% end %>
脚本/服务器输出
SQL (8.7ms) COMMIT
SQL (0.1ms) BEGIN
Image Update (0.3ms) UPDATE `images` SET `updated_at` = '2009-09-01 15:17:19', `size` = 103402 WHERE `id` = 350
Image Load (0.5ms) SELECT * FROM `images` WHERE (`images`.`thumbnail` = 'small' AND `images`.`parent_id` = 350) ORDER BY ordering ASC LIMIT 1
Image Update (0.3ms) UPDATE `images` SET `updated_at` = '2009-09-01 15:17:19', `size` = 60535 WHERE `id` = 352
Image Load (0.5ms) SELECT * FROM `images` WHERE (`images`.`thumbnail` = 'front' AND `images`.`parent_id` = 350) ORDER BY ordering ASC LIMIT 1
Image Update (0.3ms) UPDATE `images` SET `updated_at` = '2009-09-01 15:17:19', `size` = 39888 WHERE `id` = 353
Image Load (0.4ms) SELECT * FROM `images` WHERE (`images`.`thumbnail` = 'thumb' AND `images`.`parent_id` = 350) ORDER BY ordering ASC LIMIT 1
Image Update (0.3ms) UPDATE `images` SET `updated_at` = '2009-09-01 15:17:19', `size` = 3510 WHERE `id` = 351
SQL (0.9ms) COMMIT
SQL (0.1ms) BEGIN
Image Update (0.3ms) UPDATE `images` SET `updated_at` = '2009-09-01 15:17:19', `size` = 100387 WHERE `id` = 338
Image Load (0.4ms) SELECT * FROM `images` WHERE (`images`.`thumbnail` = 'small' AND `images`.`parent_id` = 338) ORDER BY ordering ASC LIMIT 1
Image Update (0.3ms) UPDATE `images` SET `updated_at` = '2009-09-01 15:17:19', `size` = 58212 WHERE `id` = 340
Image Load (0.4ms) SELECT * FROM `images` WHERE (`images`.`thumbnail` = 'front' AND `images`.`parent_id` = 338) ORDER BY ordering ASC LIMIT 1
Image Update (0.8ms) UPDATE `images` SET `updated_at` = '2009-09-01 15:17:20', `size` = 38101 WHERE `id` = 341
Image Load (0.4ms) SELECT * FROM `images` WHERE (`images`.`thumbnail` = 'thumb' AND `images`.`parent_id` = 338) ORDER BY ordering ASC LIMIT 1
Image Update (0.3ms) UPDATE `images` SET `updated_at` = '2009-09-01 15:17:20', `size` = 3241 WHERE `id` = 339
SQL (0.8ms) COMMIT
有什么想法为什么(以及我如何能阻止)attachment_fu
这样做?看起来它认为 size 属性已更改,但我看不出任何原因(在我的代码中或在 中attachment_fu
)为什么它应该这样认为。