code: function QueryBuilder(client) {
    this.client = client;
    this.and = this;
    this._single = {};
    this._statements = [];
  
    // Internal flags used in the builder.
    this._method = 'select';
    this._joinFlag = 'inner';
    this._boolFlag = 'and';
    this._notFlag = false;
  }
docs: Typically called from `knex.builder`, start a new query building chain.