如何一次将多条记录保存到数据库中

Question

我有一个 forEach 循环遍历多个对象，然后在数据库中为每个项目创建一条记录。

angular.forEach($scope.movieCredits.credits.cast, function(item){
  createActor.create({
    name:       item.name,
    character:  item.character,
    movie_id:   movieRecordID[0].id,
  })
})

虽然这确实有效，但速度很慢（有些电影有 50 多名演员，这是对数据库的大量帖子请求）。有没有更好的方法将多个对象保存到数据库中？

这是我的actor控制器中的创建函数，

def create
  Actor.find_or_create_by(movie_id: params[:movie_id], name: params[:name], character: params[:character])
  redirect_to :root
end

* 更新 *

从我的 Rails 控制台登录，

Started POST "/actors.json" for 127.0.0.1 at 2016-01-12 16:15:35 +0100
Processing by ActorsController#create as JSON
  Parameters: {"_json"=>[{"name"=>"John Travolta", "character"=>"Vincent Vega", "movie_id"=>680}, {"name"=>"Samuel L. Jackson", "character"=>"Jules Winfield", "movie_id"=>680}, {"name"=>"Uma Thurman", "character"=>"Mia Wallace", "movie_id"=>680}, {"name"=>"Bruce Willis", "character"=>"Butch Coolidge", "movie_id"=>680}, {"name"=>"Ving Rhames", "character"=>"Marsellus Wallace", "movie_id"=>680}, {"name"=>"Harvey Keitel", "character"=>"Wolf", "movie_id"=>680}, {"name"=>"Eric Stoltz", "character"=>"Lance", "movie_id"=>680}, {"name"=>"Tim Roth", "character"=>"Pumpkin", "movie_id"=>680}, {"name"=>"Amanda Plummer", "character"=>"Honey Bunny", "movie_id"=>680}, {"name"=>"Maria de Medeiros", "character"=>"Fabienne", "movie_id"=>680}, {"name"=>"Quentin Tarantino", "character"=>"Jimmie Dimmick", "movie_id"=>680}, {"name"=>"Christopher Walken", "character"=>"Captain Koons", "movie_id"=>680}, {"name"=>"Rosanna Arquette", "character"=>"Jody", "movie_id"=>680}, {"name"=>"Peter Greene", "character"=>"Zed", "movie_id"=>680}, {"name"=>"Duane Whitaker", "character"=>"Maynard", "movie_id"=>680}, {"name"=>"Angela Jones", "character"=>"Esmarelda Villalobos", "movie_id"=>680}, {"name"=>"Phil LaMarr", "character"=>"Marvin", "movie_id"=>680}, {"name"=>"Steve Buscemi", "character"=>"Buddy Holly", "movie_id"=>680}, {"name"=>"Bronagh Gallagher", "character"=>"Trudi", "movie_id"=>680}, {"name"=>"Laura Lovelace", "character"=>"Waitress", "movie_id"=>680}, {"name"=>"Frank Whaley", "character"=>"Brett", "movie_id"=>680}, {"name"=>"Burr Steers", "character"=>"Roger", "movie_id"=>680}, {"name"=>"Paul Calderon", "character"=>"Paul", "movie_id"=>680}, {"name"=>"Jerome Patrick Hoban", "character"=>"Ed Sullivan", "movie_id"=>680}, {"name"=>"Michael Gilden", "character"=>"Page for Phillip Morris", "movie_id"=>680}, {"name"=>"Gary Shorelle", "character"=>"Ricky Nelson", "movie_id"=>680}, {"name"=>"Susan Griffiths", "character"=>"Marilyn Monroe", "movie_id"=>680}, {"name"=>"Eric Clark", "character"=>"James Dean", "movie_id"=>680}, {"name"=>"Joseph Pilato", "character"=>"Dean Martin", "movie_id"=>680}, {"name"=>"Brad Blumenthal", "character"=>"Jerry Lewis (as Brad Parker)", "movie_id"=>680}, {"name"=>"Lorelei Leslie", "character"=>"Mamie van Doren", "movie_id"=>680}, {"name"=>"Emil Sitka", "character"=>"Hold Hands You Lovebirds (archive footage)", "movie_id"=>680}, {"name"=>"Brenda Hillhouse", "character"=>"Mrs. Coolidge - Butch's Mother", "movie_id"=>680}, {"name"=>"Chandler Lindauer", "character"=>"Young Butch", "movie_id"=>680}, {"name"=>"Sy Sher", "character"=>"Klondike", "movie_id"=>680}, {"name"=>"Robert Ruth", "character"=>"Sportscaster #1 - Coffee Shop", "movie_id"=>680}, {"name"=>"Rich Turner", "character"=>"Sportscaster #2", "movie_id"=>680}, {"name"=>"Don Blakely", "character"=>"Wilson's Trainer", "movie_id"=>680}, {"name"=>"Carl Allen", "character"=>"Dead Floyd Wilson", "movie_id"=>680}, {"name"=>"Karen Maruyama", "character"=>"Gawker #1", "movie_id"=>680}, {"name"=>"Kathy Griffin", "character"=>"Hit-and-run Witness", "movie_id"=>680}, {"name"=>"Venessia Valentino", "character"=>"Pedestrian / Bonnie Dimmick", "movie_id"=>680}, {"name"=>"Linda Kaye", "character"=>"Shot Woman", "movie_id"=>680}, {"name"=>"Stephen Hibbert", "character"=>"The Gimp", "movie_id"=>680}, {"name"=>"Alexis Arquette", "character"=>"Man No. 4", "movie_id"=>680}, {"name"=>"Julia Sweeney", "character"=>"Raquel", "movie_id"=>680}, {"name"=>"Lawrence Bender", "character"=>"Long Hair Yuppy Scum", "movie_id"=>680}, {"name"=>"Cie Allman", "character"=>"Winston Wolfe's Girlfriend At Party (uncredited)", "movie_id"=>680}, {"name"=>"Rene Beard", "character"=>"Bar Tender (uncredited)", "movie_id"=>680}, {"name"=>"Lori Pizzo", "character"=>"Lucky Lady (uncredited)", "movie_id"=>680}, {"name"=>"Glendon Rich", "character"=>"Drug Dealer (uncredited)", "movie_id"=>680}, {"name"=>"Devan Richardson", "character"=>"Hopalong Cassidy (uncredited)", "movie_id"=>680}, {"name"=>"Ani Sava", "character"=>"Woman in Bathroom (uncredited)", "movie_id"=>680}], "actor"=>{}}
  User Load (2.8ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = ?  ORDER BY "users"."id" ASC LIMIT 1  [["id", 1]]
   (0.1ms)  begin transaction
  SQL (0.2ms)  INSERT INTO "actors" ("created_at", "updated_at") VALUES (?, ?)  [["created_at", "2016-01-12 15:15:35.503383"], ["updated_at", "2016-01-12 15:15:35.503383"]]
   (11.9ms)  commit transaction
Redirected to http://localhost:3000/
Completed 302 Found in 31ms (ActiveRecord: 15.0ms)

Answer 1

您已使用 Ruby on Rails 标记了该问题，因此我假设您使用的是 ActiveRecord。所以，构建一个批量插入的api如下。

您的 Angular 代码应如下所示

var actors = [];
angular.forEach($scope.movieCredits.credits.cast, function(item){
  actors.push({
    name:       item.name,
    character:  item.character,
    movie_id:   movieRecordID[0].id,
  });
});
createActor.create(actors);

在你的 Rails 控制器中

def create
  actors = Actor.create(params[:actors])
  ..
  render json: actors
end

这是活动记录处理插入多条记录的方式，因为create 方法也采用如下数组

Model.create([{name: "John Doe", character: "The Hobbit", movie_id: 1}, {name: "Christian Bale", character: "Batman", movie_id: 2}])

这将对 N 条记录执行一个 SQL 查询，而不是对 N 条记录执行 N 个 SQL 查询。