CODEWITHSUNDEEP
mongodbmeteormongodb-query
flimflam57
flimflam57

Reputation: 1334

Mongo using set instead of $set

I'm using Meteor and was updating a document and had the code (by mistake):

Programs.update({ _id: id}, { set: { LessonWk1: weekArray }});

Instead of:

Programs.update({ _id: id}, { $set: { LessonWk1: weekArray }});

Turns out when I used 'set' it deleted the document when the update ran. I didn't see any 'set' command in Mongo. Just curious how the documents get deleted from 'set'.

Upvotes: 1

Views: 65

Answers (1)

Sede
Sede

Reputation: 61225

This is the expected behavior as mentioned in the documentation:

If the document contains only field:value expressions, then:

The update() method replaces the matching document with the document. The update() method does not replace the _id value.

This means that your document is replaced bu something like this:

{ _id: id, set: { LessonWk1: weekArray }}

Because it doesn't replace the _id value you can return the new document using findOne.

Programs.findOne( { _id: id } )

Upvotes: 1

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