MongooseError [ParallelSaveError]：无法并行保存（）同一个文档

Posted 2023-03-11

【中文标题】MongooseError [ParallelSaveError]：无法并行保存（）同一个文档

【英文标题】：MongooseError [ParallelSaveError]: Can't save() the same doc multiple times in parallel

【发布时间】：2020-04-11 00:24:44

【问题描述】：

我遇到了 mongoose 和 nodejs 的问题。可能是我写了错误的代码或任何其他问题，请帮忙。这是我的控制器文件。 alldata.save 给[ParallelSaveError]

let createData = async function(req,res,next) 
    let body = req.body;
    let alldata = new League(body);
    let start_time = new Date().getTime();
    try 
         await Leaguecategories.find()
                .then(async function(categories)   
                    categories.forEach(async function(category) 
                      //here i am assigning foreign key
                        alldata.league_category_id = category._id;
                       await alldata.save(function(err, book)
                            if(err)
                                console.log(err);
                            else
                            res.send(status: 0, statusCode:"success", message: "Successfully inserted.")
                            
                       );
                    )     
                )
    
    catch (error)
        return res.send(status : 1 , statusCode : "error" , message : error.message)
    

这是我的 Leaguecategories 模型

var mongoose = require('mongoose');


const league_categories = new mongoose.Schema(
    name: 
      type: String,
      required: true
    ,
    active: 
      type: String,
      required: true
    ,
    create_date: 
      type: Date,
      required: true,
      default: Date.now
    ,
    league_type_id: 
      type: String,
      required: 'league_type',
      required:true
    
  )

  module.exports = mongoose.model('Leaguecategories', league_categories)

这是我的联赛模型

var mongoose = require('mongoose');

    const league = new mongoose.Schema(
        title: 
            type: String,
            required: true
          ,
          pool_price: 
              type: Number,
              required: true
          ,
          entry_fee: 
              type: Number,
              required: true
          ,
          total_spots: 
              type: Number,
              required: true
          ,
          start_time: 
            type: Date,
            required: true
          ,
          end_time: 
            type: Date,
            required: true
          ,
          create_date: 
            type: Date,
            required: true,
            default: Date.now
          ,
          active: 
            type: String,
            required: true
          ,
          league_category_id: 
            type: String,
            ref: 'Leaguecategories',
            required:true
          
    )

    module.exports = mongoose.model('League', league)

【参考方案1】：

您必须每次都创建League 的新实例。像这样：

categories.forEach(async function(category) 
  //here i am assigning foreign key
  let alldata = new League(body);
  alldata.league_category_id = category._id;
  ...
);

建议：

您为什么同时使用async/await 和.then()？您应该只使用其中之一。此外，还有一些其他问题。

await 不能在 forEach 内部工作 每次拨打.save() 时，您都会拨打res.send()。这也可能最终引发错误。

你可以像这样重构代码。

try 
  const categories = await Leaguecategories.find();
  const promises = categories.map(function (category) 
    //here i am assigning foreign key
    let alldata = new League(body);
    alldata.league_category_id = category._id;
    return alldata.save();
  );

  await Promise.all(promises);

  res.send( status: 0, statusCode: "success", message: "Successfully inserted." )
 catch (error) 
  return res.send( status: 1, statusCode: "error", message: error.message );