Adding a Validator to a Collection
Learners will attach a JSON Schema validator using createCollection and collMod to enforce required fields and data types.
Why Schema Validation Matters
MongoDB is schema-flexible by default—any document can be inserted regardless of its shape. While this is useful in development, production databases need guardrails to prevent malformed data. MongoDB's schema validation feature lets you attach a JSON Schema rule set to a collection so that only well-formed documents can be inserted or updated, catching data quality problems at the database layer before they propagate.
JSON Schema as the Validation Language
MongoDB uses the industry-standard JSON Schema specification (draft 4) to express validation rules. You define a $jsonSchema object that declares which fields are required, what types they must be, and any additional constraints. The same format is used everywhere JSON Schema appears—in OpenAPI specs, form libraries, and now MongoDB validators.
All lessons in this course
- Adding a Validator to a Collection
- Type, Required, and Enum Constraints
- Validation Levels and Actions
- Evolving Schemas Without Downtime