PHP基于MySQL数据库对象持久层的教程
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。
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