MysqliDb::_buildCondition PHP Method

    protected function _buildCondition($operator, &$conditions)
    {
        if (empty($conditions)) {
            return;
        }
        //Prepare the where portion of the query
        $this->_query .= ' ' . $operator;
        foreach ($conditions as $cond) {
            list($concat, $varName, $operator, $val) = $cond;
            $this->_query .= " " . $concat . " " . $varName;
            switch (strtolower($operator)) {
                case 'not in':
                case 'in':
                    $comparison = ' ' . $operator . ' (';
                    if (is_object($val)) {
                        $comparison .= $this->_buildPair("", $val);
                    } else {
                        foreach ($val as $v) {
                            $comparison .= ' ?,';
                            $this->_bindParam($v);
                        }
                    }
                    $this->_query .= rtrim($comparison, ',') . ' ) ';
                    break;
                case 'not between':
                case 'between':
                    $this->_query .= " {$operator} ? AND ? ";
                    $this->_bindParams($val);
                    break;
                case 'not exists':
                case 'exists':
                    $this->_query .= $operator . $this->_buildPair("", $val);
                    break;
                default:
                    if (is_array($val)) {
                        $this->_bindParams($val);
                    } elseif ($val === null) {
                        $this->_query .= ' ' . $operator . " NULL";
                    } elseif ($val != 'DBNULL' || $val == '0') {
                        $this->_query .= $this->_buildPair($operator, $val);
                    }
            }
        }
    }