code: function where() {
      var wheres = this.grouped.where;
      if (!wheres) {
        return undefined;
      }
      var i = -1,
          sql = [];
      while (++i < wheres.length) {
        var stmt = wheres[i];
        var val = this[stmt.type](stmt);
        if (val) {
          if (sql.length === 0) {
            sql[0] = 'where';
          } else {
            sql.push(stmt.bool);
          }
          sql.push(val);
        }
      }
      return sql.length > 1 ? sql.join(' ') : '';
    }
docs: Compiles all `where` statements on the query.