Question

我无法创建记录或检查记录是否存在。我正在向“Checks”控制器提交两个条目来创建“id”和“uid”。下面的迁移：

create_checks

class CreateChecks < ActiveRecord::Migration[5.0]
  def change
    create_table :checks do |t|
      t.timestamps
    end
  end
end

add_uid_to_checks

class AddUidToChecks < ActiveRecord::Migration[5.0]
  def change
    add_column :checks, :uid, :string
  end
end

Checks_controller＃创建

def create
  @check = Check.new(check_params)

  respond_to do |format|
    if @check.save
      format.html { redirect_to @check, notice: 'Check was successfully created.' }
      format.json { render :show, status: :created, location: @check }
    else
      format.html { render :new }
      format.json { render json: @check.errors, status: :unprocessable_entity }
    end
  end
end

通过ajax提交了两个参数 - ID和UID

，它给了我以下内容

Started POST "/checks.json" for ::1 at 2016-09-05 09:36:31 -0500
Processing by ChecksController#create as JSON
  Parameters: {"id"=>"54545454", "uid"=>"23232323"}
   (0.0ms)  begin transaction
  SQL (2.0ms)  INSERT INTO "checks" ("created_at", "updated_at") VALUES (?, ?)
[["created_at", 2016-09-05 14:36:31 UTC], ["updated_at", 2016-09-05 14:36:31 UTC
]]
   (10.0ms)  commit transaction
  Rendering checks/show.json.jbuilder
  Rendered checks/_check.json.jbuilder (1.0ms)
  Rendered checks/show.json.jbuilder (9.0ms)
Completed 201 Created in 201ms (Views: 174.8ms | ActiveRecord: 12.0ms)

然后我检查它是否存在使用此控制器......

def set_check
if Check.exists?(params[:id])
  render plain: "1"
else
  render plain: "0"
end
    end

这给了我......

Started GET "/checks/54545454" for ::1 at 2016-09-05 0
9:36:37 -0500
Processing by ChecksController#show as */*
      Parameters: {"id"=>"54545454"}
Check Exists (1.0ms)  SELECT  1 AS one FROM "checks" WHERE "checks"."id" = ? L
IMIT ?  [["id", 0], ["LIMIT", 1]]
  Rendering text template
  Rendered text template (0.0ms)
Filter chain halted as :set_check rendered or redirected
Completed 200 OK in 7ms (Views: 1.8ms | ActiveRecord: 1.0ms)

并且找不到“0”。我确定我做错了什么，但我无法确定在哪里。

更多代码位：

Routes.rb相关部分：

  resources :checks

定义了set_checks（在控制器的顶部，在ChecksController＆lt; ApplicationController类的正下方）

  before_action :set_check, only: [:show, :edit, :update, :destroy]

Answer 1

ActiveRecord使用id列作为主键 - 它是一个自动递增列，因此在将记录插入表时设置该值。因此，在创建新记录时，您永远不会将ID作为参数传递。

事实上，如果你检查新创建的记录的id，它与参数：

不同

def create
  @check = Check.new(check_params)
  logger.info("id param is: #{ params[:id] }")

  respond_to do |format|
    if @check.save
      logger.info("Check id is: #{ @check.id }")
      format.html { redirect_to @check, notice: 'Check was successfully created.' }
      format.json { render :show, status: :created, location: @check }
    else
      format.html { render :new }
      format.json { render json: @check.errors, status: :unprocessable_entity }
    end
  end
end

已添加 - 如果您不打算使用主键，则不应使用id作为列名。

ActiveRecord - 我创建了一条记录，但是当我检查它是否存在时它什么也没有返回

1 个答案: