本文实例讲述了PHP基于MySQL数据库实现对象持久层的方法。分享给大家供大家参考。具体如下：
心血来潮，做了一下PHP的对象到数据库的简单持久层。
不常用PHP，对PHP也不熟，关于PHP反射的大部分内容都是现学的。
目前功能比较弱，只是完成一些简单的工作，对象之间的关系还没法映射，并且对象的成员只能支持string或者integer两种类型的。
成员变量的值也没有转义一下。。。
下面就贴一下代码：
首先是数据库的相关定义，该文件定义了数据库的连接属性：
<?php /* * Filename: config.php * Created on 2012-9-29 * Created by RobinTang * To change the template for this generated file go to * Window - Preferences - PHPeclipse - PHP - Code Templates */ // About database define("DBHOST", "localhost"); // 数据库服务器 define("DBNAME", "db_wdid"); // 数据库名称 define("DBUSER", "root"); // 登陆用户名 define("DBPSWD", "trb"); // 登录密码 ?> 下面是数据库访问的简单封装：
<?php /* * Filename: database.php * Created on 2012-9-29 * Created by RobinTang * To change the template for this generated file go to * Window - Preferences - PHPeclipse - PHP - Code Templates */ include_once("config.php"); $debug = false; $g_out = false; function out($s){ global $g_out; $g_out .= $s; $g_out .= ""; } function db_openconnect(){ $con = mysql_connect(DBHOST, DBUSER, DBPSWD); if(!mysql_set_charset("utf8", $con)){ out("set mysql encoding fail"); } if (!$con){ out("Could not connect: " . mysql_error()); } else{ if(!mysql_select_db(DBNAME, $con)){ $dbn = DBNAME; out("Could select database "$dbn" : " . mysql_error()); } $sql = "set time_zone = "+8:00";"; if(!db_onlyquery($sql, $con)){ out("select timezone fail!" . mysql_error()); } } return $con; } function db_colseconnect($con){ mysql_close($con); } function db_onlyquery($sql, $con){ $r = mysql_query($sql, $con); if(!$r){ out("query "$sql" :fail"); return false; } else{ return $r; } } function db_query($sql){ $con = db_openconnect(); $r = db_onlyquery($sql, $con); $res = false; if($r){ $res = true; } db_colseconnect($con); return $r; } function db_query_effect_rows($sql){ $con = db_openconnect(); $r = db_onlyquery($sql, $con); $res = false; if($r){ $res = mysql_affected_rows($con); if($res==0){ $res = -1; } } else{ $res = false; } db_colseconnect($con); return $res; } function db_getresult($sql){ $con = db_openconnect(); $r = db_onlyquery($sql, $con); $res = false; if($r && $arr = mysql_fetch_row($r)){ $res = $arr[0]; } db_colseconnect($con); return $res; } function db_getarray($sql){ $con = db_openconnect(); $r = db_onlyquery($sql, $con); $ret = false; if($r){ $row = false; $len = 0; $ret = Array(); $i = 0; while($arr = mysql_fetch_row($r)){ if($row == false || $len==0){ $row = Array(); $len = count($arr); for($i=0;$i<$len;++$i){ $key = mysql_field_name($r, $i); array_push($row, $key); } } $itm = Array(); for($i=0;$i<$len;++$i){ $itm[$row[$i]]=$arr[$i]; } array_push($ret, $itm); } } db_colseconnect($con); return $ret; } ?> 其实上面的两个文件都是之前写好的，持久层的东西是下面的：
<?php /* * Filename: yinxirm.php * Created on 2012-11-4 * Created by RobinTang * To change the template for this generated file go to * Window - Preferences - PHPeclipse - PHP - Code Templates */ include_once("database.php"); function SinORM_ExecSql($sql) { return db_query($sql); } function SinORM_ExecArray($sql) { return db_getarray($sql); } function SinORM_ExecResult($sql){ return db_getresult($sql); } function SinORM_GetClassPropertys($class) { $r = new ReflectionClass($class); if (!$r->hasProperty("tablename")) { throw new Exception("Class "$class" has no [tablename] property"); } $table = $r->getStaticPropertyValue("tablename"); if (!$r->hasProperty("id")) { throw new Exception("Class "$class" has no [id] property"); } $mpts = Array (); $pts = $r->getProperties(ReflectionProperty :: IS_PUBLIC); foreach ($pts as $pt) { if (!$pt->isStatic()) { array_push($mpts, $pt); } } return Array ( $table, $mpts ); } function SinORM_GetPropertyString($pts, $class, $obj = false, $noid = false) { if (is_null($pts)) { list ($tb, $pts) = SinORM_GetClassPropertys($class); } $s = false; $v = false; $l = false; foreach ($pts as $pt) { $name = $pt->name; if ($noid == false || $name != "id") { if ($l) { $s = $s . ","; } $s = $s . $name; if ($obj) { if ($l) { $v = $v . ","; } $val = $pt->getValue($obj); if (is_null($val)) $v = $v . "null"; if (is_string($val)) $v = $v . ""$val""; else $v = $v . $val; } $l = true; } } return Array ( $s, $v ); } function SinORM_GetTableName($class){ $r = new ReflectionClass($class); if (!$r->hasProperty("tablename")) { throw new Exception("Class "$class" has no [tablename] property"); } $table = $r->getStaticPropertyValue("tablename"); if (!$r->hasProperty("id")) { throw new Exception("Class "$class" has no [id] property"); } return $table; } function SinORM_ResetORM($class) { list ($tb, $pts) = SinORM_GetClassPropertys($class); $sql = "CREATE TABLE `$tb` (`id` int NOT NULL AUTO_INCREMENT"; $r = new ReflectionClass($class); $obj = $r->newInstance(); foreach ($pts as $pt) { $val = $pt->getValue($obj); $name = $pt->name; if ($name != "id") { $sql = $sql . ","; } else { continue; } if (is_null($val)) throw new Exception($class . "->" . "name must have a default value"); if (is_string($val)) $sql = $sql . "`$name` text NULL"; else $sql = $sql . "`$name` int NULL"; } $sql = $sql . ",PRIMARY KEY (`id`));"; $dsql = "DROP TABLE IF EXISTS `$tb`;"; return SinORM_ExecSql($dsql) && SinORM_ExecSql($sql); } function SinORM_SaveObject($obj) { $class = get_class($obj); list ($tb, $pts) = SinORM_GetClassPropertys($class); list ($names, $vals) = SinORM_GetPropertyString($pts, $class, $obj, true); $sql = "INSERT INTO `$tb`($names) values($vals)"; if(SinORM_ExecSql($sql)){ $q = "SELECT `id` FROM `$tb` ORDER BY `id` DESC LIMIT 1;"; $id = SinORM_ExecResult($q); if($id){ $obj->id = $id; } } return false; } function SinORM_GetObjects($class) { list ($tb, $pts) = SinORM_GetClassPropertys($class); $sql = "SELECT * from `$tb`;"; $ary = SinORM_ExecArray($sql); $res = false; if (is_array($ary)) { $res = Array (); $ref = new ReflectionClass($class); foreach ($ary as $a) { $obj = $ref->newInstance(); foreach ($pts as $pt) { $name = $pt->name; $olv = $pt->getValue($obj); $val = $a[$name]; if (is_string($olv)) $pt->setValue($obj, $val); else $pt->setValue($obj, intval($val)); } array_push($res, $obj); } } else { echo "no"; } return $res; } function SinORM_GetObject($class, $id) { list ($tb, $pts) = SinORM_GetClassPropertys($class); $sql = "SELECT * from `$tb` where `id`=$id;"; $ary = SinORM_ExecArray($sql); $res = null; if (is_array($ary) && count($ary) > 0) { $res = Array (); $ref = new ReflectionClass($class); $a = $ary[0]; $obj = $ref->newInstance(); foreach ($pts as $pt) { $name = $pt->name; $olv = $pt->getValue($obj); $val = $a[$name]; if (is_string($olv)) $pt->setValue($obj, $val); else $pt->setValue($obj, intval($val)); } return $obj; } return null; } function SinORM_Update($obj) { $class = get_class($obj); list ($tb, $pts) = SinORM_GetClassPropertys($class); $sql = "UPDATE `$tb` SET "; $l = false; foreach ($pts as $pt) { $name = $pt->name; $val = $pt->getValue($obj); if ($name == "id") continue; if ($l) $sql = $sql . ","; if (is_string($val)) $sql = $sql . "$name="$val""; else $sql = $sql . "$name=$val"; $l = true; } $sql = $sql . " WHERE `id`=$obj->id;"; return SinORM_ExecSql($sql); } function SinORM_SaveOrUpdate($obj) { if (SinORM_GetObject(get_class($obj), $obj->id) == null) { SinORM_SaveObject($obj); } else { SinORM_Update($obj); } } function SinORM_DeleteObject($obj){ $class = get_class($obj); $tb = SinORM_GetTableName($class); $sql = "DELETE FROM `$tb` WHERE `id`=$obj->id;"; return SinORM_ExecSql($sql); } function SinORM_DeleteAll($class){ $tb = SinORM_GetTableName($class); $sql = "DELETE FROM `$tb`;"; return SinORM_ExecSql($sql); } ?> 下面是使用的例子：
<?php /* * Filename: demo.php * Created on 2012-11-4 * Created by RobinTang * To change the template for this generated file go to * Window - Preferences - PHPeclipse - PHP - Code Templates */ include_once("yinxirm.php"); // 下面是一个持久对象的类的定义 // 每个持久对象类都必须有一个叫做$tablename静态成员，它表示数据库中存储对象的表名 // 类的每个成员都必须初始化，也就是必须给它一个初始值 // 成员变量只能为字符串或者整型，而且请定义成public的，只有public的成员变量会被映射 class User{ public static $tablename = "t_user"; // 静态变量，对象的表名，必须的 public $id = 0; // 对象ID,对应表中的主键，必须的，而且必须初始化为0 public $name = ""; // 姓名，必须初始化 public $age = 0; // 年龄，必须初始化 public $email = ""; // 必须初始化 } // 注意：下面的语句一定要在定义好类之后运行一下，修改了类也需要运行一下，它完成创建表的工作 // SinORM_ResetORM("User"); // 这一句只是一开始执行一次，执行之后就会自动在数据库中建立User对应的表 $user1 = new User(); // 创建一个对象 $user1->name = "TRB"; $user1->age = 22; $user1->email = "trbbadboy@qq.com"; SinORM_SaveObject($user1); // 把对象保存到数据库中 // 保存之后会自动给id的 $id = $user1->id; echo $id . "<br/>"; $user2 = SinORM_GetObject("User", $id); // 通过ID从数据库创建一个对象 echo $user2->name . "<br/>"; $user1->name = "trb"; // 改变一下 SinORM_Update($user1); // 更新到数据库 $user3 = SinORM_GetObject("User", $id); // 重新读出 echo $user3->name . "<br/>"; ?> 希望本文所述对大家的php程序设计有所帮助。
