Ruby on Rails：搜索時出現重複結果

Question

我有一個rails應用程序，允許用戶搜索數據庫中的項目。

這裏是在項目模型中的搜索功能：

def self.search(search_industry, search_role, search_techs_ids) 

    _projects = Project.scoped 

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

，這裏是我的搜索頁面的一部分

<div class="tech"> 
<%= fields_for(@project_technol) do |ab| %> 
Technologies : 
<%  tech_ids = params[:technols][:id].reject(&:blank?) unless params[:technols].nil? %> 

<%if params[:technols].nil?%> 

<%= collection_select(:technols, :id, @all_technols, :id, :tech, {}, {:multiple => true}) %> 

<% else %> 

<%= collection_select(:technols, :id, @all_technols, :id, :tech, {}, {:multiple => true, :selected => tech_ids }) %> 
<% end %> 

</div> 

這裏是我的搜索行動：

def search 

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

    @search = params[:industry], params[:role], tech_ids 

    @project_search = Project.search(*@search).order(sort_column + ' ' + sort_direction).paginated_for_index(per_page, page) 

    @search_performed = !@search.reject! { |c| c.blank? }.empty? 

    @project = Project.new(params[:project]) 

    @all_technols = Technol.all 

    @project_technol = @project.projecttechnols.build 

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

end 

我問題是，當我在搜索頁面上選擇collection_select中的所有技術並單擊搜索時，結果會顯示毫秒顯示所有記錄重複，如果他們擁有多種技術。

例如，數據庫中有3個項目。 P1，P2，P3，都有3種技術，T1，T2和T3。如果我要搜索所有3種技術，每個項目應該顯示一次，但是它們顯示3次。

有沒有人有任何想法，我可能會出錯。提前致謝。

編輯

我PARAMS搜索時：

Parameters: {"utf8"=>"✓", "client"=>"", "industry"=>"", "technols"=>{"id"=>["", "40", "41", "42", "43", "44", "46", "47", "48", "49", "50", "51", "52", "53", "54"]}, "start_date_dd"=>"", "start_date_A"=>"", "start_date_B"=>"", "status"=>"", "per_page"=>"10"} 
    User Load (0.4ms) SELECT "users".* FROM "users" WHERE "users"."id" = 1 LIMIT 1 
    Technol Load (0.3ms) SELECT "technols".* FROM "technols" 
    Project Load (0.8ms) SELECT "projects".* FROM "projects" ORDER BY client 
    Project Load (0.4ms) SELECT "projects".* FROM "projects" ORDER BY industry 
    Project Load (0.4ms) SELECT "projects".* FROM "projects" ORDER BY status 
    (1.0ms) SELECT DISTINCT COUNT(*) FROM "projects" INNER JOIN "projecttechnols" ON "projecttechnols"."project_id" = "projects"."id" INNER JOIN "technols" ON "technols"."id" = "projecttechnols"."technol_id" WHERE "technols"."id" IN (40, 41, 42, 43, 44, 46, 47, 48, 49, 50, 51, 52, 53, 54) 
    Project Load (13.2ms) SELECT DISTINCT "projects".* FROM "projects" INNER JOIN "projecttechnols" ON "projecttechnols"."project_id" = "projects"."id" INNER JOIN "technols" ON "technols"."id" = "projecttechnols"."technol_id" WHERE "technols"."id" IN (40, 41, 42, 43, 44, 46, 47, 48, 49, 50, 51, 52, 53, 54) ORDER BY project_name asc LIMIT 10 OFFSET 0 
    Technol Load (0.9ms) SELECT "technols".* FROM "technols" INNER JOIN "projecttechnols" ON "technols"."id" = "projecttechnols"."technol_id" WHERE "projecttechnols"."project_id" = 107 
    Technol Load (1.8ms) SELECT "technols".* FROM "technols" INNER JOIN "projecttechnols" ON "technols"."id" = "projecttechnols"."technol_id" WHERE "projecttechnols"."project_id" = 100 
    Technol Load (1.8ms) SELECT "technols".* FROM "technols" INNER JOIN "projecttechnols" ON "technols"."id" = "projecttechnols"."technol_id" WHERE "projecttechnols"."project_id" = 106 
    Rendered projects/search.html.erb within layouts/application (68.2ms) 
Completed 200 OK in 100ms (Views: 74.8ms | ActiveRecord: 22.8ms) 

UPDATE：

我剛剛發現了一個錯誤。

我的模型現在包含此代碼;

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

不顯示重複了，但我發現，當我搜索一個單一的技術，在顯示的結果表。我有此列：

<td><ul> 
    <% t.technols.each do |technol| %> 
    <li><%= technol.tech %><!/li> 
    <% end %> 
</ul></td> 

這用來顯示所有的技術，該項目的名單，但現在新的代碼，它只是顯示我搜索的一個。有任何想法嗎？

Answer 1

你可以嘗試使用包括而不是連接？

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

包含選項基本上做一個外部聯接，而不是內部聯接。它也渴望加載記錄，這意味着您將有一個「更大」的單個查詢而不是多個查詢。

一個很好的解釋

參見here

左連接，你可以沿着這些路線做一些見here：

if search_techs_ids.present? 
    _projects = _projects.joins("LEFT OUTER JOIN technols ON technols.id = project.technol_id") 
end