findOne() is returning the whole model instead of a document-CodePudding

I am using findOne() to extract a document. On printing the returned value its prints the correct result but on looping over it, it prints the model instead of the original document. The document in the City table is stored as -

{
 _id: 62e135519567726de42421c2,
configType: 'cityConfig'
'16': {
        cityName: 'Delhi',
        metro: true,
        tier1: true
      },
'17': {
        cityName: 'Indore',
        metro: false,
        tier1: false
      }
}

The code -

const getCities = async () => {
  const cityConfig = await City.findOne({
    configType: "cityConfig"
  });

  console.log("cityConfig - ", cityConfig);
  
  let metroCities = [];

  for(var city in cityConfig) {
    console.log("city - ", city);
    if(cityConfig[city].metro == true) { // throws an error here obviously
      metroCities.push(city);
    }
  }
  return metroCities;

};

The ouptut of cityConfig is correct, but inside the for loop, its iterating over the model instead of the document. Output -

cityPassConfig -  {
 '16': {
    cityName: 'Nagpur',
    passIssuedCities: false,
    digitalDiscountEnabledCities: false,
    bhopalIndore: false,
    mPanelCitiesForPass: false
  },
  '17': {
    cityName: 'Mumbai',
    passIssuedCities: false,
    digitalDiscountEnabledCities: false,
    bhopalIndore: false,
    mPanelCitiesForPass: false
  },
 _id: 62e288807b59432f87e32a82,
  configType: 'cityPassConfig'
}
city -  $__
city -  isNew
city -  errors
city -  $locals
city -  $op
city -  _doc
city -  $init
city -  db
city -  discriminators
city -  configType
city -  cityId
city -  configData
city -  enabled
city -  lastModifiedby
city -  _id
city -  updatedAt
city -  createdAt
.
.
.
.

I want it to just iterate over 16 and 17 (the keys of the object). How to do that? Node version - v14.15.4

CodePudding user response：

You are using Mongoose, so if you want to return the JavaScript object, you should use lean() method.

const cityConfig = await City.findOne({ configType: "cityConfig" }).lean();

If you don't use lean(), Mongoose will hydrate the document. You can read more here.

CodePudding user response：

The issue seems to be with your document:

{
    _id: 62e135519567726de42421c2,
    configType: 'cityConfig' // There should be a comma here, but not sure if that's affecting anything.
    '16': {
        cityName: 'Delhi',
        metro: true,
        tier1: true
    },
    '17': {
        cityName: 'Indore',
        metro: false,
        tier1: false
    }
}

Your '16' and '17' are siblings with configType. You should have it nested inside e.g.

{
    _id: 62e135519567726de42421c2,
    configType: 'cityConfig',
    cityConfig: [
        '16': {
            cityName: 'Delhi',
            metro: true,
            tier1: true
        },
        '17': {
            cityName: 'Indore',
            metro: false,
            tier1: false
        }
    ]
}

CodePudding user response：

You can check for keys which are numbers only.

const cityConfig = await City.findOne({
 configType: "cityConfig",
});

console.log("cityConfig - ", cityConfig);

let metroCities = [];

for (var city in cityConfig) {
 if (!isNaN(city)) {
   console.log("city - ", city);
   if (cityConfig[city].metro == true) {
     // throws an error here obviously
     metroCities.push(city);
   }
 }
}
return metroCities;
};

CodePudding user response：

By default, Mongoose queries return an instance of the Mongoose Document class, you can find the object in _doc of the result.

if you don't need all those info use .lean(), it will also make your query faster and less memory intensive.

const cityConfig = await City.findOne({ configType: "cityConfig" }).lean();

You can then iterate like you are doing right now either use .lean() or try for(var city in cityConfig._doc)