Ruby on rails RubyonRails：项目控制器中的运行时错误

我在尝试将新条目保存到数据库时遇到问题。提交时，项目应保存到项目表中，该项目中的技术应保存到名为Technols的技术表中，这些技术之间的关系存储在名为Projecttechnols的表中

这是我的新动作：

def new
    @project = Project.new
    @technol = Technol.new(params[:tech])

@all_technols = Technol.all
tech_ids = params[:technols][:id].reject(&:blank?) unless params[:technols].nil?


@project_technol = @project.projecttechnols.build





#@project_technol = Projecttechnol.new

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @project }
    end
  end

    def create
    @all_technols = Technol.all
    @project = Project.new(params[:project])

@technol = Technol.new(params[:tech])




params[:technol].each_value do |tech|

technology = Technol.find_by_tech(tech.strip)

@project_technol = @project.projecttechnols.build(:technol_id => technology.id)

end


    @project.client = params[:new_client] unless params[:new_client].blank?
    @project.project_owner = params[:new_project_owner] unless params[:new_project_owner].blank?
    @project.tech = params[:new_tech] unless params[:new_tech].blank?
    @project.role = params[:new_role] unless params[:new_role].blank?
    @project.industry = params[:new_industry] unless params[:new_industry].blank?
    @project.business_div = params[:new_business_div] unless params[:new_business_div].blank?

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

创建操作：

def new
    @project = Project.new
    @technol = Technol.new(params[:tech])

@all_technols = Technol.all
tech_ids = params[:technols][:id].reject(&:blank?) unless params[:technols].nil?


@project_technol = @project.projecttechnols.build





#@project_technol = Projecttechnol.new

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @project }
    end
  end

    def create
    @all_technols = Technol.all
    @project = Project.new(params[:project])

@technol = Technol.new(params[:tech])




params[:technol].each_value do |tech|

technology = Technol.find_by_tech(tech.strip)

@project_technol = @project.projecttechnols.build(:technol_id => technology.id)

end


    @project.client = params[:new_client] unless params[:new_client].blank?
    @project.project_owner = params[:new_project_owner] unless params[:new_project_owner].blank?
    @project.tech = params[:new_tech] unless params[:new_tech].blank?
    @project.role = params[:new_role] unless params[:new_role].blank?
    @project.industry = params[:new_industry] unless params[:new_industry].blank?
    @project.business_div = params[:new_business_div] unless params[:new_business_div].blank?

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

和我的3款车型：

Project.rb

class Project < ActiveRecord::Base
  attr_accessible  :edited_first_name, :edited_last_name, :first_name, :last_name, :business_div, :client, :customer_benifits, :edited_date, :end_date, :entry_date,  :financials, :industry, :keywords, :lessons_learned, :project_name, :project_owner, :role, :start_date, :status, :summary, :tech , :technols

validates_presence_of :business_div, :client, :customer_benifits, :end_date,  :financials, :industry, :keywords, :lessons_learned, :project_name, :project_owner, :role, :start_date, :status, :summary




has_many :projecttechnols
has_many :technols, :through => :projecttechnols


def self.like(text); "%#{text}%"; end

  def self.search(search_client, search_industry, search_role, search_techs_ids, search_business_div, search_project_owner,  search_status, search_start_date_dd, search_start_date_A, search_start_date_B,  search_keywords)
    # start with a scoped query, to apply more scopes on it afterwards
    _projects = Project.scoped 
    # then, for each of the parameters, apply the scope only if present
    if search_client.present?
      _projects = _projects.where ['client LIKE ?', like(search_client)] 
    end
    if search_industry.present?
      _projects = _projects.where ['industry LIKE ?', like(search_industry)]
    end
    if search_role.present?
      _projects = _projects.where ['role LIKE ?', like(search_role)]
    end

#_projects = _projects.joins(:technols).
 #             where("technols.id" => search_techs_ids)



#_projects = _projects.joins(:projecttechnols).where("projecttechnols.id" => search_techs_ids)


if search_techs_ids.present?
_projects = _projects.joins(:technols).where("technols.id" => search_techs_ids)
end



    if search_business_div.present?
      _projects = _projects.where ['business_div LIKE ?', like(search_business_div)]
    end
    if search_project_owner.present?
      _projects = _projects.where ['project_owner LIKE ?', like(search_project_owner)]
    end

     if search_status.present?
      _projects = _projects.where ['status LIKE ?', like(search_status)]
    end



todays_date = DateTime.now.to_date

if !search_start_date_A.blank? or !search_start_date_B.blank?
    search_start_date_A = Date.parse(search_start_date_A).strftime("%Y-%m-%d")
    search_start_date_B = Date.parse(search_start_date_B).strftime("%Y-%m-%d")
    todays_date = nil
    search_start_date_dd = nil

    end

if search_start_date_dd.blank?
    todays_date = nil
end


if search_start_date_A.present? or search_start_date_B.present?

      _projects = _projects.where [' DATE(start_date) BETWEEN ? AND ?', search_start_date_A, search_start_date_B]
    end


                if search_start_date_dd.present?
      _projects = _projects.where ['DATE(start_date) BETWEEN ? AND ?', search_start_date_dd, todays_date]
    end




    if search_keywords.present?
      _projects = _projects.where ['keywords LIKE ?', like(search_keywords)]
    end
    # now you have applied only the present scopes. return the result, and watch 
    # the query as it executes.
    _projects
  end


def self.paginated_for_index(projects_per_page, current_page)
    paginate(:per_page => projects_per_page, :page => current_page)
  end

end

class Technol < ActiveRecord::Base
  attr_accessible :tech

has_many :projecttechnols
has_many :projects, :through => :projecttechnols
end

class Projecttechnol < ActiveRecord::Base
  attr_accessible :project_id, :technol_id

belongs_to :technol
belongs_to :project
end

这些是我的情妇：

    {"utf8"=>"✓",
 "authenticity_token"=>"sPyJbgBKTxa9iHWF9r0Gg/0R/v0l0/e8KwXpPebzdus=",
 "project"=>{"project_name"=>"",
 "status"=>"Active",
 "client"=>"",
 "business_div"=>"",
 "project_owner"=>"",
 "start_date"=>"01-10-2012",
 "entry_date"=>"2012-10-03",
 "end_date"=>"09-10-2012",
 "role"=>"",
 "industry"=>"",
 "summary"=>"",
 "lessons_learned"=>"",
 "customer_benifits"=>"",
 "financials"=>"",
 "keywords"=>""},
 "new_client"=>"",
 "new_business_div"=>"",
 "new_project_owner"=>"",
 "technol"=>{"tech"=>"TESTER"},
 "new_role"=>"",
 "new_industry"=>"",
 "commit"=>"Save New Project"}

我是rails新手，所以请在尝试帮助我时记住这一点。一切帮助都将不胜感激。提前谢谢

更新：

工作代码

def create
    @all_technols = Technol.all
    @project = Project.new(params[:project])

@technol = Technol.new(params[:tech])




params[:technol].each_value do |tech|

technology = Technol.find_or_create_by_tech(tech.strip)

@project_technol = @project.projecttechnols.build(:technol_id => technology.id)

end

---

筛选所有内容有点困难，但每当您看到以下信息：

Called id for nil, which would mistakenly be ...

这意味着您试图对未正确加载的对象调用方法（.id）。如果我不得不猜测，这将是你在这里的创建操作：

technology = Technol.find_by_tech(tech.strip)
  @project_technol = @project.projecttechnols.build(:technol_id => technology.id)
end

特别是

technology.id

。你确定这一行：

technology = Technol.find_by_tech(tech.strip)

---

是否返回预期结果？如果用

Technol.first

替换它，是否会停止错误？如果是这样，

find\u by\u tech

将失败。

更改为

Technol。首先

将保存项目。但它将技术表中的第一项技术保存到了该项目中。我希望

TESTER

成为新技术。即使

TESTER

不在表中。这只是我在设置新项目时在新视图中输入的一项技术，只是为了确认诊断；）你的评论解释了这个问题。您试图添加一项新技术，但是

find\u by\u tech

当然找不到它，因此

technology.id

失败。如果您想添加创建新技术的可能性，请将包含

find_by_tech

的行更改为：

technology=Technol.find_或_create_by_tech（tech.strip）

，您应该能够动态添加新技术！