Datatypes Declaration in MongoDB for dbPointer, Symbol

[Jayaprakash_Nagappan]

Hi Team,

How to use below Data Type while creating collections.

dbPointer
javascript
symbol
javascriptWithScope
minKey
maxKey

Assist me with proper syntax and place of use.

Regards,
Jayaprakash

[kanikasingla]

Hi @Jayaprakash_08777,

@Jayaprakash_08777

Assist me with proper syntax and place of use.

You may find below documents useful:

https://docs.mongodb.com/manual/reference/bson-types/

https://docs.mongodb.com/manual/core/schema-validation/

Also, if this doesn’t help, please elaborate more on your scenario.

Kanika

[007_jb (O Brown)]

To expand a little:

1. dbPointer - Deprecated as per ¹

2. javascript -

   // Create test records
   use test
   db.collection.insertMany([
      {a: 1},
      {a: 2},
      {a: 3}
   ])
   

   // Insert JS code
   db.system.js.save(
      {
         _id: "fnAdd",
         value: function (x){ return ++x; },
         description: "Increments x by 1"
      }
   )
   

   Result:
   

   

3. symbol - Deprecated as per ¹

4. javascriptWithScope -
   Only possible via a driver or Compass and not Mongo shell. The scope argument is what makes it a javascriptWithScope type.
   

   // The inserted doc will will look this
   {
      "_id": "fnWithScope",
      "value" : {
         "code" : "function (x){ return x * x; }",
         "scope" : {}
      }
   }
   

   NB: Prefixing the "code" and "scope" fields with $ will enable you use the above doc in Compass to create a javascriptWithScope type, however, any attempts to do this in the Mongo shell is futile as it will result in value being an object type.

   Result:
   

   

5. minKey - Internal use only as per ¹ but you can also reference doc ²

6. maxKey - Internal use only as per ¹ but you can also reference doc ²

Both javascript types are poorly documented, moreso the with-scope type (there’s hardly any documentation for this across multiple drivers and the Mongo shell).

References:
¹ the first link Kanika posted
² MongoDB Extended JSON (v2)
Store JS function in server
$where documentation