code: protected function joinStringFromArray($dataMember, $sep = ' AND ')
      {
          if (empty($this->$dataMember)) {
              return 0;
          }
          $count = count($this->$dataMember);
          //var_dump($this->$dataMember);
          for($i=0; $i<$count; $i++) {
              $statement = $this->{$dataMember}[$i];
              $this->query .= ' '.$statement[2].' JOIN '.$statement[0].' ON ';
              $sCount = count($statement[1]);
              for($j=0; $j<$sCount; $j++) {
                  $this->query .= $this->getArrayJoin($dataMember, $i, $j);
                  if ($sCount-1 != $j) {
                      $this->query .= $sep;
                  }
              }
          }
      }
docs: For creating a JOIN string expression from the database class arrays holding JOIN
  data.