updating mongo object on basis of website object

Question

There is mongo object

    { 
        "_id" : ObjectId("5aa3abda9ff4d600da5b0168"), 
        "regionId" : NumberInt(3526), 
        "regionName" : "So Cal", 
        "categories" : [
            "Other", 
            "Topicals", 
            "Tincture", 
            "Cannabis", 
            "Edibles", 
            "Extracts", 
            "Prerolled", 
            "Vape Cartridges"
        ]
}

Website object comes like this

{ "regionId" : 3526, 
        "regionName" : "So Cal", 
        "categories" : [
            "Other",
            "Seeds", 
            "Tincture", 
            "Cannabis", 
            "Edibles", 
            "Extracts", 
            "Prerolled", 
            "Vape Cartridges"
        ]
}

FINAL OBJECT SHOULD BE LIKE

  { 
            "_id" : ObjectId("5aa3abda9ff4d600da5b0168"), 
            "regionId" : NumberInt(3526), 
            "regionName" : "So Cal", 
            "categories" : [
                "Other",
                "Seeds",
                "Tincture", 
                "Cannabis", 
                "Edibles", 
                "Extracts", 
                "Prerolled", 
                "Vape Cartridges"
            ]
    }

This object comes from a website and categories elements keep on changing. what I want to achieve is if some new element comes in categories then it should be inserted in my mongo and if some element is not there in the website and there in my mongo, it should be deleted from my mongo object.

$addToSet will only solve the problem if some new element is added but what in case of delete ?

(I'm an absolute beginner) in mongo please suggest how to achieve this.

Possible duplicate of [Can mongo upsert array data?](https://stackoverflow.com/questions/13588342/can-mongo-upsert-array-data) — Ayush Gupta, Mar 10 '18 at 10:33
$addToSet will only solve the problem if some new element is added but what in case of delete @AyushGupta — Rohan Singh, Mar 10 '18 at 10:38
do you mean, if an array item coming from the website is not in the categories array in mongo, you want to insert it and if it is not in the array item but in mongo you want to remove the value? — 0.sh, Mar 10 '18 at 10:44
do value from the website is extacly like the document represented in your question, or it comes as an array? — 0.sh, Mar 10 '18 at 10:50
value from website comes like { "regionId" : 3526, "regionName" : "So Cal", "categories" : [ "Other", "Seeds", "Tincture", "Cannabis", "Edibles", "Extracts", "Prerolled", "Vape Cartridges" ] } @0.sh — Rohan Singh, Mar 10 '18 at 10:52

score 0 · Answer 1 · answered Mar 10 '18 at 13:40

the update command can solve this

// value coming from website
 var obj = { 
        "regionId" : 3526, 
        "regionName" : "So Cal", 
         "categories" : [
            "Other",
            "Seeds", 
            "Tincture", 
            "Cannabis", 
            "Edibles", 
            "Extracts", 
            "Prerolled", 
            "Vape Cartridges"
        ]
 }

> db.drugs.insert(obj);
> db.drugs.find({regionId: obj.regionId}).pretty();
{
    "_id" : ObjectId("5aa3ba064a7f0d521aa4dacb"),
    "regionId" : 3526,
    "regionName" : "So Cal",
    "categories" : [
        "Other",
        "Seeds",
        "Tincture",
        "Cannabis",
        "Edibles",
        "Extracts",
        "Prerolled",
        "Vape Cartridges"
    ]
}

// assuming the category changes
// push adds an element to categories
> obj.categories.push("concain");
> db.drugs.update( { regionId: obj.regionId }, obj ); 
> db.drugs.find({regionId: obj.regionId}).pretty()
{
   "_id" : ObjectId("5aa3ba064a7f0d521aa4dacb"),
   "regionId" : 3526,
   "regionName" : "So Cal",
   "categories" : [
      "Other",
      "Seeds",
      "Tincture",
      "Cannabis",
      "Edibles",
      "Extracts",
      "Prerolled",
      "Vape Cartridges",
      "hello"
  ]
}

// remove hello from the categories
> obj.categories.pop();
> db.drug.update( { regionId: obj.regionId }, obj );
> db.drugs.find({regionId: obj.regionId}).pretty();
{
  "_id" : ObjectId("5aa3ba064a7f0d521aa4dacb"),
  "regionId" : 3526,
  "regionName" : "So Cal",
  "categories" : [
     "Other",
     "Seeds",
     "Tincture",
     "Cannabis",
     "Edibles",
     "Extracts",
     "Prerolled",
     "Vape Cartridges"
  ]
}

updating mongo object on basis of website object

1 Answers1