PHP基于MySQL数据库实现对象持久层的方法

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 .= "\r\n";
  }
  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: sinorm.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("sinorm.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。