Specify Validation Level for Existing Documents

Specify validation rules with strict validation level.

Add a validator to the contacts collection with strict validationLevel:

db.runCommand( {
   collMod: "contacts",
   validator: { $jsonSchema: {
      bsonType: "object",
      required: [ "phone", "name" ],
      properties: {
         phone: {
            bsonType: "string",
            description: "phone must be a string and is required"
         },
         name: {
            bsonType: "string",
            description: "name must be a string and is required"
         }
      }
   } },
   validationLevel: "strict"
} )

Because the validationLevel is strict, when any document is updated, MongoDB checks that document for validation.

Test the validation.

The following update commands modify both documents in the contacts collection such that neither of the documents are consistent with the validation rule which requires name to be a string:

db.contacts.updateOne(
   { _id: 1 },
   { $set: { name: 10 } }
)
db.contacts.updateOne(
   { _id: 2 },
   { $set: { name: 20 } }
)

Observe results.

Both update operations fail. MongoDB returns the following output for each operation:

 MongoServerError: Document failed validation
 Additional information: {
   failingDocumentId: <id>,
   details: {
     operatorName: '$jsonSchema',
     schemaRulesNotSatisfied: [
       {
         operatorName: 'properties',
         propertiesNotSatisfied: [
           {
             propertyName: 'name',
             description: 'name must be a string and is required',
             details: [
               {
                 operatorName: 'bsonType',
                 specifiedAs: { bsonType: 'string' },
                 reason: 'type did not match',
                 consideredValue: <value>,
                 consideredType: 'int'
               }
             ]
           }
         ]
       },
       {
         operatorName: 'required',
         specifiedAs: { required: [ 'phone', 'name' ] },
         missingProperties: [ 'phone' ]
       }
     ]
   }
 }

Specify validation rules with moderate validation level.

Add a validator to the contacts collection with moderate validationLevel:

db.runCommand( {
   collMod: "contacts",
   validator: { $jsonSchema: {
      bsonType: "object",
      required: [ "phone", "name" ],
      properties: {
         phone: {
            bsonType: "string",
            description: "phone must be a string and is required"
         },
         name: {
            bsonType: "string",
            description: "name must be a string and is required"
         }
      }
   } },
   validationLevel: "moderate"
} )

Because the validationLevel is moderate:

• If you update the document with _id: 1, MongoDB applies the new validation rules because the existing document meets the validation requirements.

• If you update the document with _id: 2, MongoDB does not apply the new validation rules because the existing document does not meet the validation requirements.

Test the validation.

The following update commands modify both documents in the contacts collection such that neither of the documents are consistent with the validation rule which requires name to be a string:

db.contacts.updateOne(
   { _id: 1 },
   { $set: { name: 10 } }
)
db.contacts.updateOne(
   { _id: 2 },
   { $set: { name: 20 } }
)

Observe results.

MongoDB returns the following output for each operation:

// _id: 1
MongoServerError: Document failed validation
Additional information: {
  failingDocumentId: 1,
  details: {
    operatorName: '$jsonSchema',
    schemaRulesNotSatisfied: [
      {
        operatorName: 'properties',
        propertiesNotSatisfied: [
          {
            propertyName: 'name',
            description: 'name must be a string and is required',
            details: [
              {
                operatorName: 'bsonType',
                specifiedAs: { bsonType: 'string' },
                reason: 'type did not match',
                consideredValue: 10,
                consideredType: 'int'
              }
            ]
          }
        ]
      }
    ]
  }
}
// _id: 2
{
   acknowledged: true,
   insertedId: null,
   matchedCount: 1,
   modifiedCount: 0,
   upsertedCount: 0
}

The output shows that:

• The update fails for the document with _id: 1. This document met the initial validation requirements, and MongoDB applies validation rules to this document.

• The update succeeds for the document with _id: 2. This document did not meet the initial validation requirements, and MongoDB does not apply validation rules to this document.