How to remove a subdocument inside an object using Mongoose

Question

I am trying to remove a subdocument with id from an object using Mongoose. I tried to use update fucntion in Moongose, but after running the script Im gets the status "Ok: 1", but the status is "nModified: 0". I tried to use the following script:

Page.update({"subPages._id": req.body.ID}, {"$unset":{"subPages":1}}, function (re,q) { console.log(q); }); 

This script removes all attached documents from the object. Here is my json:

 { "_id" : ObjectId("585a7a7c2ec07b40ecb093d6"), "name_en" : "Head Page", "name_nl" : "Head Page", "slug_en" : "Head-page", "slug_nl" : "hoofd-menu", "content_en" : "<p>Easy (and free!) You should check out our premium features.</p>", "content_nl" : "<p>Easy (and free!) You should check out our premium features.</p>", "date" : ISODate("2016-12-21T12:50:04.374Z"), "is_footerMenu" : 0, "is_headMenu" : 0, "visible" : 1, "__v" : 0, "subPages" : [ { "content_nl" : "<p>Easy (and free!) You should check out our premium features.</p>", "content_en" : "<p>Easy (and free!) You should check out our premium features.</p>", "slug_nl" : "Sub-page", "slug_en" : "Sub-page", "name_nl" : "Subpage", "name_en" : "Subpage", "date" : ISODate("2016-12-21T14:58:44.733Z"), "subPages" : [], "is_footerMenu" : 0, "is_headMenu" : 0, "visible" : 1, "_id" : ObjectId("585a98a46f657b52489087a8") }, { "content_nl" : "<p>Easy (and free!) You should check out our premium features.</p>", "content_en" : "<p>Easy (and free!) You should check out our premium features.</p>", "slug_nl" : "Subpage", "slug_en" : "Subpage", "name_nl" : "Subpage1", "name_en" : "Subpage1", "date" : ISODate("2016-12-21T14:58:54.819Z"), "subPages" : [], "is_footerMenu" : 0, "is_headMenu" : 0, "visible" : 1, "_id" : ObjectId("585a98ae6f657b52489087a9") } ] 

}

I want to remove a subobject with id

 585a98a46f657b52489087a8 

How can i do this?

Answer 1

To remove an element (subdocument) from an array, you need $ pull it.

 Page.update({ 'subPages._id': req.body.ID }, { $pull: { subPages: { _id: req.body.ID } } }, function (error, result) { console.log(result); }); 

If you want to delete all subdocuments (i.e. make subPages empty), you can $ set its value to an empty array.

 Page.update({ 'subPages._id': req.body.ID }, { $set: { subPages: [] } }, function (error, result) { console.log(result); }); 

Hope this helps.