一、SQL語句

View Code -- -- 數據庫: `booklist` ---- ---------------------------------------------------------- -- 表的結構 `authors` --CREATE TABLE IF NOT EXISTS `authors` (`id` int(11) NOT NULL AUTO_INCREMENT,`name` varchar(20) DEFAULT NULL,PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ;-- -- 轉存表中的數據 `authors` --INSERT INTO `authors` (`id`, `name`) VALUES (1, 'admin'), (2, 'user');-- ---------------------------------------------------------- -- 表的結構 `books` --CREATE TABLE IF NOT EXISTS `books` (`id` int(11) NOT NULL AUTO_INCREMENT,`ISBN` varchar(20) CHARACTER SET utf8 DEFAULT NULL,`title` varchar(50) CHARACTER SET utf8 DEFAULT NULL,`publisher` int(11) DEFAULT NULL,PRIMARY KEY (`id`),UNIQUE KEY `ISBN` (`ISBN`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=50 ;-- -- 轉存表中的數據 `books` --INSERT INTO `books` (`id`, `ISBN`, `title`, `publisher`) VALUES (1, '12345678', '測試書本1', 1), (2, '12345679', '測試書本2', 1), (3, '0.72667894766357', '測試書本3', 1), (4, '0.1224353342526', '測試書本4', 1), (5, '0.43213985900594', '測試書本5', 1), (6, '0.79339332300554', '測試書本6', 1), (7, '0.67054706874354', '測試書本7', 1), (8, '0.97255540543474', '測試書本8', 1), (9, '0.8511358516767', '測試書本9', 1), (10, '0.33801307281294', '測試書本10', 1), (11, '0.13665783976825', '測試書本11', 1), (12, '0.66925001113606', '測試書本12', 1), (13, '0.93627656710919', '測試書本13', 1), (14, '0.67363283287141', '測試書本14', 1), (15, '0.55933449376313', '測試書本15', 1), (16, '0.77577400093505', '測試書本16', 1), (17, '0.2008665541195', '測試書本17', 1), (18, '0.67701079852601', '測試書本18', 1), (19, '0.78245436100518', '測試書本19', 1), (20, '0.88123944018152', '測試書本20', 1), (21, '0.058834148625689', '測試書本21', 1), (22, '0.65045245331754', '測試書本22', 1), (23, '0.075759851444289', '測試書本23', 1), (24, '0.42744192800246', '測試書本24', 1), (25, '0.9099301164131', '測試書本25', 1), (26, '0.26732482879173', '測試書本26', 1), (27, '0.60683382545303', '測試書本27', 1), (28, '0.23219467162359', '測試書本28', 1), (29, '0.34047191249251', '測試書本29', 1), (30, '0.0057755783254053', '測試書本30', 1), (31, '0.0074621848831532', '測試書本31', 1), (32, '0.019984220173195', '測試書本32', 1), (33, '0.077534576950161', '測試書本33', 1), (34, '0.32772025496487', '測試書本34', 1), (35, '0.40599757470749', '測試書本35', 1), (36, '0.046827139376502', '測試書本36', 1), (37, '0.016143003493681', '測試書本37', 1), (38, '0.94023363007254', '測試書本38', 1), (39, '0.65273917061532', '測試書本39', 1), (40, '0.44299499359261', '測試書本40', 1), (41, '0.25675748685073', '測試書本41', 1), (42, '0.95480248420947', '測試書本42', 1), (43, '0.0037399912287854', '測試書本43', 1), (44, '0.15429253424918', '測試書本44', 1), (45, '0.76024272829317', '測試書本45', 1), (46, '0.33833606945196', '測試書本46', 1), (47, '0.41095219311393', '測試書本47', 1), (48, '0.039752787947424', '測試書本48', 1), (49, '0.96590739112898', '測試書本49', 1);-- ---------------------------------------------------------- -- 表的結構 `book_authors` --CREATE TABLE IF NOT EXISTS `book_authors` (`bookid` int(11) NOT NULL DEFAULT '0',`authorid` int(11) NOT NULL DEFAULT '0',PRIMARY KEY (`bookid`,`authorid`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1;-- -- 轉存表中的數據 `book_authors` --INSERT INTO `book_authors` (`bookid`, `authorid`) VALUES (1, 2), (2, 2), (3, 2), (4, 2), (5, 2), (6, 2), (7, 2), (8, 2), (9, 2), (10, 2), (11, 1), (12, 1), (13, 1), (14, 1), (15, 1), (16, 2), (17, 2), (18, 2), (19, 2), (20, 2), (21, 2), (22, 2), (23, 2), (24, 2), (25, 2), (26, 2), (27, 1), (28, 1), (29, 1), (30, 1), (31, 1), (32, 1), (33, 1), (34, 1), (35, 1), (36, 1), (37, 1), (38, 2), (39, 2), (40, 2), (41, 2), (42, 2), (43, 2), (44, 2), (45, 1), (46, 1), (47, 1), (48, 1), (49, 2);-- ---------------------------------------------------------- -- 表的結構 `publisher` --CREATE TABLE IF NOT EXISTS `publisher` (`id` int(11) NOT NULL AUTO_INCREMENT,`name` varchar(20) CHARACTER SET utf8 DEFAULT NULL,PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ;-- -- 轉存表中的數據 `publisher` --INSERT INTO `publisher` (`id`, `name`) VALUES (1, '清華大學'), (2, '北京大學');

二、視圖 show.php

<?phprequire_once dirname(__FILE__).'/booklist.class.php';require_once dirname(__FILE__).'/page.class.php';$dbConn = new mysqli('localhost','root','123456','booklist');$dbConn->query("set names utf8");$booksPerPage = 10;$page = isset($_GET['page']) ? $_GET['page'] : 1;$bookList = new BookList($dbConn);$bookPage = new Page($bookList,$page,$booksPerPage); ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title> 圖書俱樂部 </title> </head> <body><p>Showing books</p><?phpprintf('%d-%d of %d',$bookPage->getFirstIndex(),$bookPage->getLastIndex(),count($bookList));?><table><thead><th>Title</th><th>Author</th><th>Publisher</th></thead><tbody><?phpforeach($bookPage as $key => $book){printf('<tr><td>%s</td><td>%s</td><td>%s</td></tr>',$book['title'],$book['author'],$book['publisher']);}?></tbody></table><ul><?php$totalPages = ceil(count($bookList) / $booksPerPage);if($page > 1){printf('<li><a href="?page=%d">Prev</a></li>',$page-1);}for($i = 1 ; $i <= $totalPages ; $i++){if( $i == $page){printf('<li>%d</li>', $i);} else {printf('<li><a href="?page=%d">%d</a></li>',$i,$i);}}if($page < $totalPages){printf('<li><a href="?page=%d">Next</a></li>', $page+1);}?></ul> </body> </html> <!-- //系統執行步驟 一、實例化bookList類和page類，bookList實例連接數據庫，bookPage實例傳入bookList實例，當前頁，偏移量 二、外部迭代類bookPage實例調用了rewind()方法，通過getInnerIterator()方法獲取內部迭代實例，調用了bookList實例的seek方法 三、bookList實例的seek方法設置了當前索引并獲取索引內容 四、bookPage實例的foreach執行了valid()方法，該方法調用了bookList實例的key方法,返回當前迭代實例的key 五、bookPage實例通過驗證，執行current()方法，該方法調用了bookList實例的current方法,返回當前內容 六、bookPage實例接著key()方法，該方法調用了bookList實例的key方法,返回當前主鍵 七、bookPage實例進入next方法，該方法調用了bookList實例的next方法,指針下移 -->

三、BookList類 booklist.class.php

<?php class BookList implements Iterator,Countable,SeekableIterator,ArrayAccess {private $pages = array();private $currentPag = 1;private $database = null;private $booksPerPage = 10;private $totalBooks = 0;private $deletions = array();public function __construct($database){$this->database = $database;if($result = $this->database->query("select count(*) from books")){if($row = $result->fetch_row()){$this->totalBooks = $row[0];}}}/* 迭代接口 */function rewind(){$this->currentPage = 1;if( array_key_exists(1,$this->pages) ){reset($this->pages[$i]);}}function current(){return current($this->touchPage());}function key(){return key($this->touchPage()) + $this->booksPerPage * ($this->currentPage -1);}function next(){$page = & $this->touchPage();next($page);if( key($page) === null && count($page) == $this->booksPerPage){$this->currentPage++;$page = & $this->touchPage();reset($page);}return current($page);}function valid(){$page = & $this->touchPage();return (key($page) !== null);}//查詢數據private function & touchPage($pageNo = false){if($pageNo === false){$pageNo = $this->currentPage;}if(! array_key_exists($pageNo,$this->pages)){if( $pageNo > ceil($this->count() / $this->booksPerPage)){$this->pages[$pageNo] = array();}else{$start = ($pageNo-1)* $this->booksPerPage + $this->getAdjustmentForPage($pageNo);$sql = "select `ISBN`,title,(select group_concat(`name`) from `book_authors` as t2 join `authors` as t3 on t2.authorid = t3.id where t2.bookid = t1.id) as `author`,`t4`.`name` as publisher from `books` as t1 join `publisher` as t4 on t1.publisher = t4.id limit $start,{$this->booksPerPage}";$result = $this->database->query($sql);while ($row = $result->fetch_array(MYSQLI_ASSOC)){$temp_array[] = $row;}$this->pages[$pageNo] = $temp_array;}}$temp = & $this->pages[$pageNo];return $temp;}/* 計數接口 */public function count(){return $this->totalBooks;}/* 索引接口 */public function seek($index){if($index < 0 || $index > $this->totalBooks){throw new OutOfBoundsException();}$this->currentPage = (int) floor($index / $this->booksPerPage) +1;$page = & $this->touchPage();reset($page);for($i = $index % $this->booksPerPage; $i>0 ; $i--){next($page);}}/* 數組訪問接口*/public function offsetExists($offset){echo 'offsetExists';return ( $offset > 0 && $offset < count($this) );}public function offsetGet($offset){echo 'offsetGet';$pageOfOffset = (int)floor($offset / $this->booksPerPage) + 1;$page = & $this->touchPage($pageOfOffset);return $page[$offset / $this->booksPerPage];}public function offsetSet($offset,$newValue){echo 'offsetSet'; $pageOfOffset = (int)floor($offset / $this->booksPerPage) + 1;$page = & $this->touchPage($pageOfOffset);$page[$offset % $this->booksPerPage] = $newValue;}public function offsetUnset($offset){echo 'offsetUnset'; $pageOfOffset = (int)floor($offset / $this->booksPerPage) + 1;$page = & $this->touchPage($pageOfOffset);$this->deletions[$pageOfOffset] ++;ksort($this->deletions);unset($page[$offset % $this->booksPerPage]);$page = array_values($page);while(is_array($this->pages[$pageOfOffset+1])){$this->pages[$pageOfOffset][] = array_shift($this->pages[++$pageOfOffset]);}$record = ($pageOfOffset -1)*$this->booksPerPage + count($this->pages[$pageOfOffset]) + $this->getAdjustmentForPage($pageOfOffset);if($result = $this->database->query("select * from books limit $record,1")){$this->pages[$pageOfOffset][] = $result->fetch_object();}$this->totalBooks --;}private function getAdjustmentForPage($pageNo){$adjust = 0;for(reset($this->deletions);key($this->deletions) !== null && key($this->deletions) < $pageNo;next($this->deletions)){$adjust += current($this->deletions);}return $adjust;} } ?>

四、Page類 page.class.php

<?php class Page extends IteratorIterator {private $page;private $currentItem;public $itemsPerPage;public function __construct(Iterator $iterator,$page,$itemsPerPage){parent::__construct($iterator);$this->page = $page;$this->itemsPerPage = $itemsPerPage;$this->rewind();}public function getFirstIndex(){return ($this->page-1) * $this->itemsPerPage;}public function getLastIndex(){return $this->getFirstIndex() + $this->itemsPerPage;}function valid(){return ( $this->currentItem != $this->itemsPerPage && $this->getInnerIterator()->key() !== null);}function rewind(){$currentItem = 0;$this->getInnerIterator()->seek( $this->getFirstIndex() );}function next(){if( $this->currentItem < $this->itemsPerPage){$this->currentItem ++;$this->getInnerIterator()->next();}} function current(){return ($this->currentItem != $this->itemsPerPage ? $this->getInnerIterator()->current() : null);}function key(){return ($this->currentItem != $this->itemsPerPage ? $this->getInnerIterator()->key() : null);}} ?>

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代碼打包下載：PHP迭代設計模式--booklist.zip

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轉載于:https://www.cnblogs.com/linzhenjie/archive/2013/03/14/2958639.html

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