Assuming I have a collection in MongoDB with 5000 records, each containing something similar to:
{
"occupation":"Doctor",
"name": {
"first":"Jimmy",
"additional":"Smith"
}
Is there an easy way to rename the field "additional" to "last" in all documents? I saw the $rename operator in the documentation but I'm not really clear on how to specify a subfield.
You can use:
db.foo.update({}, {$rename:{"name.additional":"name.last"}}, false, true);
Or to just update the docs which contain the property:
db.foo.update({"name.additional": {$exists: true}}, {$rename:{"name.additional":"name.last"}}, false, true);
The false, true in the method above are: { upsert:false, multi:true }. You need the multi:true to update all your records.
Or you can use the former way:
remap = function (x) {
if (x.additional){
db.foo.update({_id:x._id}, {$set:{"name.last":x.name.additional}, $unset:{"name.additional":1}});
}
}
db.foo.find().forEach(remap);
In MongoDB 3.2 you can also use
db.students.updateMany( {}, { $rename: { "oldname": "newname" } } )
The general syntax of this is
db.collection.updateMany(filter, update, options)
https://docs.mongodb.com/manual/reference/method/db.collection.updateMany/
You can use the $rename field update operator:
db.collection.update(
{},
{ $rename: { 'name.additional': 'name.last' } },
{ multi: true }
)
Anyone could potentially use this command to rename a field from the collection (By not using any _id):
dbName.collectionName.update({}, {$rename:{"oldFieldName":"newFieldName"}}, false, true);
see FYI
This nodejs code just do that , as @Felix Yan mentioned former way seems to work just fine , i had some issues with other snipets hope this helps.
This will rename column "oldColumnName" to be "newColumnName" of table "documents"
var MongoClient = require('mongodb').MongoClient
, assert = require('assert');
// Connection URL
//var url = 'mongodb://localhost:27017/myproject';
var url = 'mongodb://myuser:[email protected]:portNumber/databasename';
// Use connect method to connect to the server
MongoClient.connect(url, function(err, db) {
assert.equal(null, err);
console.log("Connected successfully to server");
renameDBColumn(db, function() {
db.close();
});
});
//
// This function should be used for renaming a field for all documents
//
var renameDBColumn = function(db, callback) {
// Get the documents collection
console.log("renaming database column of table documents");
//use the former way:
remap = function (x) {
if (x.oldColumnName){
db.collection('documents').update({_id:x._id}, {$set:{"newColumnName":x.oldColumnName}, $unset:{"oldColumnName":1}});
}
}
db.collection('documents').find().forEach(remap);
console.log("db table documents remap successfully!");
}
I am using ,Mongo 3.4.0
The $rename operator updates the name of a field and has the following form:
{$rename: { <field1>: <newName1>, <field2>: <newName2>, ... } }
for e.g
db.getCollection('user').update( { _id: 1 }, { $rename: { 'fname': 'FirstName', 'lname': 'LastName' } } )
The new field name must differ from the existing field name. To specify a in an embedded document, use dot notation.
This operation renames the field nmae to name for all documents in the collection:
db.getCollection('user').updateMany( {}, { $rename: { "add": "Address" } } )
db.getCollection('user').update({}, {$rename:{"name.first":"name.FirstName"}}, false, true);
In the method above false, true are: { upsert:false, multi:true }.To update all your records, You need the multi:true.
Rename a Field in an Embedded Document
db.getCollection('user').update( { _id: 1 }, { $rename: { "name.first": "name.fname" } } )
use link : https://docs.mongodb.com/manual/reference/operator/update/rename/
