_getCols example

            if (empty($this->_primary)) {
                $this->_primary[1] = "id";
                $this->_identity = 1;
            }
        } else if (!is_array($this->_primary)) {
            $this->_primary = array(1 => $this->_primary);
        } else if (isset($this->_primary[0])) {
            array_unshift($this->_primary, null);
            unset($this->_primary[0]);
        }

        $cols = $this->_getCols();
        if (! array_intersect((array) $this->_primary, $cols) == (array) $this->_primary) {
            throw new Zend_Db_Table_Exception("Primary key column(s) ("
                . implode(',', (array) $this->_primary)
                . ") are not columns in this table ("
                . implode(',', $cols)
                . ")");
        }
    }

    /** * Returns a normalized version of the reference map * * @return array */