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在对邮件进行分页时,是否将“分页”删除组中的邮件

will-paginate ruby-on-rails

0

martins · 技术社区 · 6 年前

我正在使用will-paginate对组内的帖子进行分页。一个组可能有许多帖子,我不想同时显示所有帖子。出于某种奇怪的原因,我注意到当我这样做的时候,数据库中有很多帖子被删除了。 @group.posts = paginated_posts 如*组\控制器*中所示。

我不在@group上保存,为什么要删除这些帖子?

先测试

 69     it "Pagination â get one group and its posts" do
 70       10.times { Fabricate(:post, group: @group, user: @user) }
 71       puts "POST COUNT BEFORE #{@group.posts.count}"
 72       # byebug
 73       get group_path(@group, posts_per_page: 3)
 74       puts "POST COUNT AFTER #{@group.posts.count}"
 75       expect(response).to have_http_status(200)
 76       expect(@group).to be_present
 77     end

测试输出

Groups
  GET /group/:group_id?posts_per_page=10&posts_page=2
POST COUNT BEFORE 12
POST COUNT AFTER 3

组控制器.rb

  9   def show
 10     paginated_posts = @group.posts.paginate(
 11       page: params[:posts_page],
 12       per_page: params[:posts_per_page] || 100000,
 13     )
 14     @group.posts = paginated_posts
 15     render json: @group
 16   end

原木

  (0.3ms)  RELEASE SAVEPOINT active_record_1
Started GET "/groups/33?posts_per_page=3" for 127.0.0.1 at 2018-09-18 12:52:13 +0000
Processing by GroupsController#show as HTML
  Parameters: {"posts_per_page"=>"3", "id"=>"33"}
  User Load (2.1ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2  [["id", "78913bd2-4c72-4c73-ba75-421e154c830b"], ["LIMIT", 1]]
  Group Load (1.4ms)  SELECT  "groups".* FROM "groups" WHERE "groups"."id" = $1 LIMIT $2  [["id", 33], ["LIMIT", 1]]
  Post Load (2.2ms)  SELECT  "posts".* FROM "posts" WHERE "posts"."group_id" = $1 LIMIT $2 OFFSET $3  [["group_id", 33], ["LIMIT", 3], ["OFFSET", 0]]
  Post Load (0.3ms)  SELECT "posts".* FROM "posts" WHERE "posts"."group_id" = $1  [["group_id", 33]]
   (0.4ms)  SAVEPOINT active_record_1
  Comment Load (0.5ms)  SELECT "comments".* FROM "comments" WHERE "comments"."post_id" = $1  [["post_id", 156]]
  PostImage Load (0.3ms)  SELECT "post_images".* FROM "post_images" WHERE "post_images"."post_id" = $1  [["post_id", 156]]
  Post Destroy (0.3ms)  DELETE FROM "posts" WHERE "posts"."id" = $1  [["id", 156]]
  Comment Load (0.3ms)  SELECT "comments".* FROM "comments" WHERE "comments"."post_id" = $1  [["post_id", 157]]
  PostImage Load (0.3ms)  SELECT "post_images".* FROM "post_images" WHERE "post_images"."post_id" = $1  [["post_id", 157]]
  Post Destroy (0.3ms)  DELETE FROM "posts" WHERE "posts"."id" = $1  [["id", 157]]
  Comment Load (0.3ms)  SELECT "comments".* FROM "comments" WHERE "comments"."post_id" = $1  [["post_id", 158]]

1 回复 | 直到 6 年前

1

0

SteveTurczyn 6 年前

@group.posts = ... 不会像你想象的那样工作。如果您有一对多关系,并且为现有的 group 对象,记录集去除这个 group.id 立即使用外键。不需要保存。

所以当你这样做的时候

@group.posts = paginated_posts

分页后的职位分配给协会和关联中的所有其他记录都将从关联中删除。立刻。它们不一定被删除,但不再属于 @post

你可能想改变你的 #to_json …也许加

attr_accessor :page_of_posts

然后在你的控制器里

@group.page_of_posts = paginated_posts

并确保 page_of_posts 是JSON中呈现的内容。其他人可能会提出更好的方法。