MongoDB finding nested properties-CodePudding

So I have a document and model that is structured like this

{
   "name":"root",
   "children":[
      {
         "_id":1,
         "name":"A",
         "children":[
            {
               "_id":2,
               "name":"A child1",
               "children":[
                  
               ]
            }
         ]
      },
      {
         "_id":3,
         "name":"B",
         "children":[
            {
               "_id":4,
               "name":"B child1",
               "children":[
                  {
                     "_id":5,
                     "name":"B1 child1",
                     "children":[
                        {
                           "_id":6,
                           "name":"B1-1 child1",
                           "children":[
                              
                           ]
                        }
                     ]
                  }
               ]
            }
         ]
      }
   ]
}

if I wanted to find children of A or B of root I can go

db.treeModel.find({'treeModel.children': 1}
db.treeModel.find({'treeModel.children': 3}

however, it doesn't seem to work on the ids of the children of the individual nodes. Does mongo or mongoose support this or am I missing an operator?

CodePudding user response：

you need _id in the path (and to omit "treeModel") like:

db.treeModel.find({'children._id': 1})
db.treeModel.find({'children._id': 3})

keep in mind that this will still return the entire parent document

mongo/mongoose does not support recursive nested document lookups in a find directly. if you have max depth, you can use multiple $or conditions

db.treeModel.find({
  $or: [
    { 'children._id': 1 },
    { 'children.children._id': 1 },
    { 'children.children.children._id': 1 },
  ]
});

otherwise for recursive nested, you may need to redo you data structures so you can use $graphLookup in an aggregation