Method countDocuments

src/collection.ts:831–852

* Gets the number of documents matching the filter. * For a fast count of the total documents in a collection see {@link Collection#estimatedDocumentCount| estimatedDocumentCount}. * * Due to countDocuments using the $match aggregation pipeline stage, certain query operators cannot be used

(
    filter: Filter<TSchema> = {},
    options: CountDocumentsOptions & Abortable = {}
  )

   * @see https://www.mongodb.com/docs/manual/reference/operator/query/centerSphere/#op._S_centerSphere
   */
  async countDocuments(
    filter: Filter<TSchema> = {},
    options: CountDocumentsOptions & Abortable = {}
  ): Promise<number> {
    const pipeline = [];
    pipeline.push({ $match: filter });

    if (typeof options.skip === 'number') {
      pipeline.push({ $skip: options.skip });
    }

    if (typeof options.limit === 'number') {
      pipeline.push({ $limit: options.limit });
    }

    pipeline.push({ $group: { _id: 1, n: { $sum: 1 } } });

    const cursor = this.aggregate<{ n: number }>(pipeline, options);
    const doc = await cursor.next();
    await cursor.close();
    return doc?.n ?? 0;
  }

  /**
   * The distinct command returns a list of distinct values for the given key across a collection.