Method aggregate

src/model.js:2019–2069

* Run an aggregation method on the specified field * * @param {string} attribute The attribute to aggregate over. Can be a field name or * * @param {string} aggregateFunction The function to use for aggregation, e.g. sum, max etc. * @param {object} [options] Qu

(attribute, aggregateFunction, options)

   * @returns {Promise<DataTypes|object>} Returns the aggregate result cast to `options.dataType`, unless `options.plain` is false, in which case the complete data result is returned.
   */
  static async aggregate(attribute, aggregateFunction, options) {
    options = Utils.cloneDeep(options);

    // We need to preserve attributes here as the `injectScope` call would inject non aggregate columns.
    const prevAttributes = options.attributes;
    this._injectScope(options);
    options.attributes = prevAttributes;
    this._conformIncludes(options, this);

    if (options.include) {
      this._expandIncludeAll(options);
      this._validateIncludedElements(options);
    }

    const attrOptions = this.rawAttributes[attribute];
    const field = attrOptions && attrOptions.field || attribute;
    let aggregateColumn = this.sequelize.col(field);

    if (options.distinct) {
      aggregateColumn = this.sequelize.fn('DISTINCT', aggregateColumn);
    }

    let { group } = options;
    if (Array.isArray(group) && Array.isArray(group[0])) {
      noDoubleNestedGroup();
      group = _.flatten(group);
    }
    options.attributes = _.unionBy(
      options.attributes,
      group,
      [[this.sequelize.fn(aggregateFunction, aggregateColumn), aggregateFunction]],
      a => Array.isArray(a) ? a[1] : a
    );

    if (!options.dataType) {
      if (attrOptions) {
        options.dataType = attrOptions.type;
      } else {
        // Use FLOAT as fallback
        options.dataType = new DataTypes.FLOAT();
      }
    } else {
      options.dataType = this.sequelize.normalizeDataType(options.dataType);
    }

    Utils.mapOptionFieldNames(options, this);
    options = this._paranoidClause(this, options);

    const value = await this.queryInterface.rawSelect(this.getTableName(options), options, aggregateFunction, this);
    return value;
  }

  /**
   * Count the number of records matching the provided where clause.