如何使用nodejs在mongodb的每个文档中添加数字到字段

Question

我的收藏有一个phonenumber 字段。我想在电话号码前加 91。

{
"_id": "6137392141bbb7723",
"email": "brooke@cagle.com",
"lastname": "Cagle",
"firstname": "Brooke",
"phonenumber":9000000001
},
{
"_id": "6137392141bbe30723",
"email": "brooke@cagle.com",
"lastname": "Cagle",
"firstname": "Brooke",
"phonenumber":9000000002
}

我想像这样更新我的收藏。

{
"_id": "6137392141bbb7723",
"email": "brooke@cagle.com",
"lastname": "Cagle",
"firstname": "Brooke",
"phonenumber":919000000001
},
{
"_id": "6137392141bbe30723",
"email": "brooke@cagle.com",
"lastname": "Cagle",
"firstname": "Brooke",
"phonenumber":919000000002
}

我正在尝试使用此代码，但它没有更新字段。

var x = await User.find({});
        x.forEach(async function(d)
            { 
                var phone = d.phonenumber;  
                var newPhoneNumber = 910000000000+phone;
                console.log(newPhoneNumber);

                //update 
            await User.updateMany({},{$set:{phonenumber:newPhoneNumber}},
                {
                    new: true, 
                    runValidators : true
                });
            })

对于所有这样的文档，我只得到一个值：

{
"_id": "6137392141bbb7723",
"email": "brooke@cagle.com",
"lastname": "Cagle",
"firstname": "Brooke",
"phonenumber":919000000001
},
{
"_id": "6137392141bbe30723",
"email": "brooke@cagle.com",
"lastname": "Cagle",
"firstname": "Brooke",
"phonenumber":919000000001
},
{
"_id": "6137392141bbe30723",
"email": "brooke@cagle.com",
"lastname": "Cagle",
"firstname": "Brooke",
"phonenumber":919000000001
}

我不知道这种做法是否正确。

Answer 1

我找到了解决办法。也许，这行得通，

let mobile = 9876543210;
let phone = `91${mobile}`;
let final = Number(phone)
console.log(typeof(final), final+3);

所以，

var phone = d.phonenumber;
var newPhoneNumber = Number(`91${phone}`);
console.log(newPhoneNumber);

了解有关 Number() 的更多信息：https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number

Answer 2

Playground

db.collection.update({},
//To match all documents
[{
  $set: {
    key: {
      $toInt: {
        $concat: [
          "91",
          {
            $toString: "$key"
          }
        ]
      }
    }
  }
}
],
//Concatenate 91 and the value in the field
{multi: true
})

这适用于 4.2 的 mongo 版本。这是用于更新查询的聚合管道。

Reference

编辑：

您会遇到溢出错误。在这种情况下，您可以使用 toLong。

db.mybooks.update({},
//To match all documents
[{
  $set: {
    key: {
      $toLong: {
        $concat: [
          "91",
          {
            $toString: "$key"
          }
        ]
      }
    }
  }
}
],
//Concatenate 91 and the value in the field
{multi: true
})

这是一段经过测试的代码。