how to validate mongodb embedded document

Question

MongoDB 3.2 has this nice validation feature. However, in this doc it only shows me how to do the validation on first level fields. If I have the following embedded document to insert, how could I set the validation rule?

{"name": {
          "first_name": "xx",
          "last_name": "yy"
         }
}

I've tried the following but it doesn't work,

db.createCollection( "name_collection",
    { validator: { $and:
        [
            {name.first_name: {$type: "string"}},
            {name.last_name: {$type: "string"}}
        ]
    }
)

Thanks in advance.

score 3 · Accepted Answer · answered Mar 16 '16 at 01:29

Here are the test codes, it works well

> db.createCollection('name', {validator: {$and: [{"name.first_name": {$type: 'string'}}, {"name.last_name": {$type: 'string'}}]}})
{ "ok" : 1 }

It seems you should add "" to name.last_name,

Test it with valid data

> db.name.insert({name: {first_name: 'xx', last_name: 'yy'}})
WriteResult({ "nInserted" : 1 })

Test it with invalid data

> db.name.insert({name: {first_name: 'xx', last_name: 3}})
WriteResult({
        "nInserted" : 0,
        "writeError" : {
                "code" : 121,
                "errmsg" : "Document failed validation"
        }
})

> db.name.find()
{ "_id" : ObjectId("56e8b644f33ed6e7f3c57f90"), "name" : { "first_name" : "xx",
"last_name" : "yy" } }

also, do you think it's possible to have $or in type? such as "first_name" can be type "string" or "null"? — yyforyongyu, Mar 16 '16 at 07:32

Saleem · Answer 2 · 2016-03-16T01:59:56.970

Well you have couple errors in your code snippet.

Your db.createCollection doesn't have matching braches. It should look like

db.createCollection("name_collection", {
  validator: { $and:[
    {'name.first_name': {$type: "string"}},
    {'name.last_name': {$type: "string"}}
  ]}
})

To verify if validation is working or not, try inserting partial data

 db.name_collection.insert({name:{first_name:0, last_name:0}})

See I'm just assigning numeric value to first_name and last_name so validation should fail.

After execution of above query, It gives following error.

WriteResult({
    "nInserted" : 0,
    "writeError" : {
        "code" : 121,
        "errmsg" : "Document failed validation"
    }
})

But if I assign text as pasted below, insertion should succeed which does.

db.name_collection.insert({name:{first_name:'f_name', last_name:'l_name'}})

Result:

WriteResult({ "nInserted" : 1 })

Hope this is what are you looking.

This is exactly what I was looking for! Thanks a lot! – yyforyongyu Mar 16 '16 at 04:23 — yyforyongyu, Mar 16 '16 at 04:23

how to validate mongodb embedded document

2 Answers2