MongoDB Add Fields Depends on Name?-CodePudding

db.getCollection("user").aggregate([
   { $match : { fname : "test1" } },
   { $addFields: { email_address : "[email protected]" } },
   { $match : { fname : "test2" } },
   { $addFields: { email_address : "[email protected]" } }
])

I just want to add email address depends on fname value. This code works only when there's no test2 so works once but don't repeat. is there any ways I can repeat match and addfields?

CodePudding user response：

You can use $switch for your case.

db.collection.aggregate([
  {
    "$addFields": {
      "email_address": {
        "$switch": {
          "branches": [
            {
              "case": {
                $eq: [
                  "$fname",
                  "test1"
                ]
              },
              "then": "[email protected]"
            },
            {
              "case": {
                $eq: [
                  "$fname",
                  "test2"
                ]
              },
              "then": "[email protected]"
            }
          ]
        }
      }
    }
  }
])

Here is the Mongo playground for your reference.

CodePudding user response：

In the generalized case (in case it is applicable):

db.getCollection("user").aggregate([
   { $addFields: { email_address : {$concat: ["$fname", "@gmail.com"]} }}
])