Validation Rules

Business

Configure JSON Schema validation rules to enforce data integrity and consistency.

Overview

MongoDB validation rules ensure documents match a defined schema before being inserted or updated.

Creating Validation Rules

Schema Format

Use JSON Schema to define validation:

{
  "$jsonSchema": {
    "bsonType": "object",
    "required": ["email", "name"],
    "properties": {
      "email": {
        "bsonType": "string",
        "pattern": "^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}$",
        "description": "Valid email address required"
      },
      "name": {
        "bsonType": "string",
        "minLength": 1,
        "maxLength": 100
      },
      "age": {
        "bsonType": "int",
        "minimum": 0,
        "maximum": 120,
        "description": "Age in years"
      },
      "status": {
        "enum": ["active", "inactive", "pending"],
        "description": "Account status"
      }
    }
  }
}

Validation Levels

Strict

Rejects any document that doesn't match the schema.

Use when:

• Starting a new collection
• Data quality is critical
• All applications follow the schema

Moderate

Warns about invalid documents but allows insertion.

Use when:

• Migrating existing collections
• Gradual schema enforcement
• Some flexibility needed

Common Validation Patterns

Required Fields

{
  "required": ["email", "name", "createdAt"]
}

Type Constraints

{
  "properties": {
    "age": { "bsonType": "int" },
    "email": { "bsonType": "string" },
    "active": { "bsonType": "bool" }
  }
}

Enum Values

{
  "status": {
    "enum": ["draft", "published", "archived"]
  }
}

Nested Objects

{
  "address": {
    "bsonType": "object",
    "required": ["city", "country"],
    "properties": {
      "city": { "bsonType": "string" },
      "country": { "bsonType": "string" },
      "postalCode": { "bsonType": "string" }
    }
  }
}

Testing Validation

Before applying validation:

1. Test with sample documents
2. Check existing documents for compliance
3. Fix invalid documents
4. Enable validation

Monitoring Validation

View validation errors:

• Failed insert/update attempts
• Error messages and reasons
• Affected documents

What's Next?

• Schema Management
• Bulk Operations