Validator in MongoDB does not work - mongodb

Question

I recently started working with MongoDB (version 3.2.9) and wanted to try the validation capabilities it had, as I like database-level consistency.
I know I can, and should only, do this validation in the business logic, as I already do.
But it feels nice having an additional layer of security.
I tried adding a collection category with an _id of type 'int', name of type 'string' and desc of type 'string'.
These values should all exist, but restrictions on the content are not given.
Now, following the manual, I ended up with the following code:
db.createCollection('category', {
validator: { $or:
[
{ _id: { $and: [ { $exists: true },
{ $type: 'int' } ] } },
{ name: { $and: [ { $exists: true },
{ $type: 'string' } ] } },
{ desc: { $and: [ { $exists: true },
{ $type: 'string' } ] } }
]
}
})
However, with this simple structure already, MongoDB complains:
{ "ok" : 0, "errmsg" : "unknown operator: $and", "code" : 2 }
Now, I have found this similar question, but just went and tried to put multiple constraints directly inside the $or arrays:
db.createCollection('category', {
validator: { $or:
[
{ _id: { $exists: true } },
{ _id: { $type: 'int' } },
{ name: { $exists: true } },
{ name: { $type: 'string' } },
{ desc: { $exists: true } },
{ desc: { $type: 'string' } }
]
}
})
But now, while it does create the collection like it should, I can now execute any of the following insert commands:
db.category.insert({})
db.category.insert({_id: 17, name: '', desc: 'valid'})
db.category.insert({_id: 42, name: 42, desc: ''})
db.category.insert({_id: 43, name: '', desc: 42})
db.category.insert({_id: '', name: 42, desc: 42})
db.category.find() now returns
{ "_id" : ObjectId("57e19650b10ab85eca323684") }
{ "_id" : 17, "name" : "", "desc" : "valid" }
{ "_id" : 42, "name" : 42, "desc" : "" }
{ "_id" : 43, "name" : "", "desc" : 42 }
{ "_id" : "", "name" : 42, "desc" : 42 }
As a last resort, I tried changing the $or operator to an $and, as it should need all rules to be valid, not just at least one.
db.createCollection('category', {
validator: { $and:
[
{ _id: { $exists: true } },
{ _id: { $type: 'int' } },
{ name: { $exists: true } },
{ name: { $type: 'string' } },
{ desc: { $exists: true } },
{ desc: { $type: 'string' } }
]
}
})
With this approach which seems the most rational to me, it however does not work at all. No matter which of the above mentioned inserts I tried using, mind you there's one valid out of the 5, none works, all giving me the same error:
WriteResult({
"nInserted" : 0,
"writeError" : {
"code" : 121,
"errmsg" : "Document failed validation"
}
})
As stated above, a call to db.version() returns 3.2.9, and I am running the default MongoDB 64-bit distribution on a Windows machine with only the --dbpath parameter set to a previously empty directory.

Answer 1

Please provide the 32-bit integer value using the function NumberInt(). Otherwise, it is interpreted as Double.
The following insert should successfully insert a document into collection.
Success scenario:-
db.category.insert({_id: NumberInt(17), name: "aaaa", desc: "valid"})
Failure scenario:-
db.category.insert({_id: NumberInt(42), name: 42, desc: ''})