更新嵌套几次对象的 MongoDB 问题

Question

Hey guys I have got a problem with updating value of key in the collection using Meteor / Mongo

 data: { 'id': id, 'fb_id': fbId, 'name': fbName, 'access_token': fbAccessToken, 'symbol': fbSymbol, 'config': { 'get_started': { 'payload': getStarted }, 'persistent_menu': [ { 'locale': 'default', 'call_to_actions': [ { 'type': 'postback', 'title': persistentMenu1, 'payload': 'menu' }, { 'type': 'postback', 'title': persistentMenu2, 'payload': 'knowledge_base' }, { 'type': 'nested', 'title': persistentMenu3, 'call_to_actions': [ { 'type': 'postback', 'title': nestedPersistentMenu1, 'payload': 'subscription' }, { 'type': 'postback', 'title': nestedPersistentMenu2, 'payload': 'tth' } ] } ], 'composer_input_disabled': false }, { 'locale': 'pl_PL', 'call_to_actions': [ { 'type': 'postback', 'title': persistentMenu1, 'payload': 'menu' }, { 'type': 'postback', 'title': persistentMenu2, 'payload': 'knowledge_base' }, { 'type': 'nested', 'title': persistentMenu3, 'call_to_actions': [ { 'type': 'postback', 'title': 'Subskrypcja', 'payload': 'subscription' }, { 'type': 'postback', 'title': 'Konsultant', 'payload': 'tth' } ] } ], 'composer_input_disabled': false } ], 'greeting': [ { 'locale': 'default', 'text': somethingNew }, { 'locale': 'pl_PL', 'text': greetingsText } ] }, 'created_at': '2017-06-05T06:00:37.759455Z', 'updated_at': updatedAt } })

I need to get to second element in "greeting" array and change value of 'text' which is "greetingsText" at the moment

I tried to do so using console in the browser by typing this code

Collection.update({_id: "some_id"}, {$set: {fanpageInfo: {config: {"greeting.2": {text: "tata"}}}}}) but it doesnt work unfortunately

there is error saying "update failed:

MongoError: The dotted field 'greeting.2' in 'fanpageInfo.config.greeting.2' is not valid for storage." 

And to be honest I am not sure if I am targeting it properly - I checked docs and asked google but there are just simple tutorials.

Thanks in advance for any help

Answer 1

First, your greeting array has only 2 elements, so by using greeting.2 you're attempting to modify third element (zero-based indexes).

Second, you should use dot notation to modify just one particular field:

{ $set: { "fanpageInfo.config.greeting.1.text": "tata" } }

I've changed 2 to 1 in this update. If you will attempt to use 2 instead — it will create another document in array with just text: "tata" inside.

Answer 2

FIND QUERY:

You need to go through these links as below:

Meteor Specific find-nth-element-of-array-in-mongo-collection-meteor

Mongo Specific get-n-th-element-of-an-array-in-mongodb

Simple for finding you need to use slice like ChatRooms.findOne( {}, { chatIds: { $slice: 1 } } ) ;

UPDATE QUERY

You can try

Collection.update({_id: "some_id"}, {$set: {'config.greeting.1.text': 'tata'}});

If there is anything at all like fanpageInfo as parent field of config then update query shall be Collection.update({_id: "some_id"}, {$set: {'fanpageInfo.config.greeting.1.text': 'tata'}});

I ran your above data in mongodb and it works fine with above query. Image is below

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