stratadb / ProjectionSpec

Type Alias: ProjectionSpec<T>

type ProjectionSpec<T> = { readonly [K in keyof T]?: 1 | 0 };

Defined in: src/query-options-types.ts:116

Projection specification for field selection in query results.

Type Parameters

T

T

The document type being queried

Remarks

Controls which fields are included in or excluded from query results. Uses MongoDB-style projection syntax:

• 1 or true: Include the field
• 0 or false: Exclude the field

Important rules:

• Cannot mix inclusion and exclusion (except for id field)
• Either specify fields to include OR fields to exclude
• The id field is always included unless explicitly excluded

Example

type User = Document<{
  name: string;
  email: string;
  password: string;
  age: number;
  createdAt: Date;
}>;

// ✅ Include specific fields (exclude all others)
const publicFields: ProjectionSpec<User> = {
  name: 1,
  email: 1,
  age: 1
  // password, createdAt excluded
};

// ✅ Exclude specific fields (include all others)
const withoutPassword: ProjectionSpec<User> = {
  password: 0
  // name, email, age, createdAt included
};

// ✅ Exclude multiple fields
const minimalUser: ProjectionSpec<User> = {
  password: 0,
  createdAt: 0
};

// ✅ Exclude id field
const noId: ProjectionSpec<User> = {
  id: 0,
  name: 1,
  email: 1
};

// Usage with collection
const users = await collection.find(
  { status: 'active' },
  { projection: { name: 1, email: 1 } }
);