1、什么类,什么是对象?
比如:拿个人来说
一个可以说是一个对象而他的年龄,身高,性格,样貌等可以说是他的类,
2、自定义类与实例化,要求必须将属性私有化,通过公共接口__set()和get()进行访问:
实例
实例 <?php // demo.php 文件 require 'demoName.php'; // 构造方法必须在创建对象时传入参数 $demoName = new demoName('冰冰',29,12000); // 访问成员属性,如果对象中有该属性就返回该成员属性值,没有就返回:无此属性 echo $demoName->name,'<br>'; // 调用__get()魔术方法 echo $demoName->age = 30,'<br>';//调用__set()魔术方法 echo $demoName->name = 'dada';//调用__set()魔术方法 // 访问__construct函数 echo $demoName->__construct('天',28,20000); // demoName.php 文件 class demoName{ private $name; private $age; private $stature; // 声明构造方法: 对象属性的初始化,在类实例化的时候,自动调用 public function __construct($name, $age,$stature){ $this->name = $name; $this->age = $age; $this->stature = $stature; } // 当外面直接访问私有成员属性$name的时候被自动调用 public function __get($name){ $msg = null; if (isset($this->$name)) { $msg = $this->$name; } else { $msg = '无此属性'; } return $msg; } // 设置器 当外面直接设置私有成员属性$name的时候被自动调用 public function __set($name, $value){ $this->$name = $value; } /*class demoName{ private $name; private $age; private $stature; // 声明构造方法: 对象属性的初始化,在类实例化的时候,自动调用 public function __construct($name, $age,$stature){ $this->name = $name; $this->age = $age; $this->stature = $stature; } // 当外面直接访问私有成员属性$name的时候被自动调用 public function __get($name){ $msg = null; if (isset($this->$name)) { $msg = $this->$name; } else { $msg = '无此属性'; } return $msg; } // 设置器 当外面直接设置私有成员属性$name的时候被自动调用 public function __set($name, $value){ $this->$name = $value; } }*/ /*class demoName{ private $name; private $age; private $gong; // 构造方法:初始化。在实例化后自动调用 public function __construct($name, $age,$gong){ $this->name = $name; $this->age = $age; $this->gong = $gong; } // 获取器。当外面直接访问私有成员属性$name的时候被自动调用 public function __get($name) { $msg = null; if(isset($this->$name)){ $msg = $this->$name; }else{ $msg = '无此属性'; } return $msg; } //设置器。当外面直接设置私有成员属性$name的时候被自动调用 public function __set($name, $value) { $this->$name = $value; } }*/ /*class demoName{ private $name; private $age; private $gong; // 构造方法 public function __construct($name,$age,$gong){ $this->name=$name; $this->age=$age; $this->gong=$gong; return '姓名:'.$this->name.',年龄:'.$this->age.',月薪:'.$this->gong; } // 获取器。当外面直接访问私有成员属性$name的时候被自动调用 public function __get($name) { // 外部访问,如果成员变量就返回其成员变量属性值,如果没有就返回:无此属性 return isset($this->$name) ? $this->$name : '无此属性'; } // 设置器。当外面直接设置私有成员属性$name的时候被自动调用 public function __set($name, $value) { $this->$name = $value; } } */ /* class demoName{ private $name; private $age; private $gong; // 构造方法 public function __construct($name,$age,$gong){ $this->name=$name; $this->age=$age; $this->gong=$gong; } // 获取器 public function __get($name) { return isset($this->$name) ? $this->$name : '没有属性'; } // 设置器 public function __set($name, $value) { $this->$name = $value; } }*/
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3、数据库连接:
实例
<?php // demo.php 文件 header('Content-Type: text/html; charset=UTF-8'); require 'demo1.php'; // 把系统报错的Warning信息去除,留下自定义错误 // error_reporting(E_ALL ^E_WARNING); /* error_reporting(E_ALL ^E_WARNING); error_reporting(E_ALL ^E_WARNING); error_reporting(E_ALL ^E_WARNING); error_reporting(E_ALL ^E_WARNING); error_reporting(E_ALL ^E_WARNING); error_reporting(E_ALL ^E_WARNING); error_reporting(E_ALL ^E_WARNING); error_reporting(E_ALL ^E_WARNING); error_reporting(E_ALL ^E_WARNING); */ // 创建数据库连接 $mysql = new mysqli($db['host'],$db['user'],$db['pass']); /* $mysql = new mysqli($db['host'],$db['user'],$db['pass']); mysql = new mysqli($db['host'],$db['user'],$db['pass']); $mysql = new mysqli($db['host'],$db['user'],$db['pass']); $mysql = new mysqli($db['host'],$db['user'],$db['pass']); $mysql = new mysqli($db['host'],$db['user'],$db['pass']); */ // 判断是否连接成功 if ($mysql->connect_errno) { // 自定义错误信息,返回的错误信息为字符串类型 die('连接错误'.$mysql->connect_errno.':'.$mysql->connect_error); } /* // 判断是否连接成功 if($mysql->connect_errno){ // 自定义错误信息,返回的错误信息为字符串类型 die('连接错误:'.$mysql->connect_errno.':'.$mysql->connect_error); } // 判断是否连接成功 if($mysql->connect_orrno){ // 自定义错误信息,返回的错误信息为字符串类型 die('连接错误:'.$mysql->connect_orrno.':'.$mysql->connect_error); } // 判断是否连接成功 if($mysql->connect_errno){ // 自定义错误信息,返回的错误信息为字符串类型 die('连接错误:'.$mysql->connect_errno.':'.$mysql->connect_error); } if($mysql->connect_errno){ die('连接错误:'.$mysql->connect_errno.':'.$mysql->connect_error); }*/ echo '<h1>连接成功</h1>'; // 设置默认数据库 $mysql->select_db($db['name']); /* $mysql->select_db($db['name']); $mysql->select_db($db['name']); $mysql->select_db($db['name']); $mysql->select_db($db['name']); $mysql->select_db($db['name']); */ //默认字符编码集 $mysql->set_charset($db['charset']); /* $mysql->set_charset($db['charset']); $mysql->set_charset($db['charset']); $mysql->set_charset($db['charset']); $mysql->set_charset($db['charset']); $mysql->set_charset($db['charset']); */ // demo1.php 文件 $db=[ 'host' => '127.0.0.1', 'user' => 'root', 'pass' => 'root1', 'name' => 'php', 'charset' => 'utf8', ];
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4、数据库增删改查:
实例
// 在 name_user 表中 给 name和salary字段添加增加数据为 天弘 20000 INSERT INTO `name_user` (`name`,`salary`) VALUES ('天弘',20000) /* INSERT INTO `name_user` (`name`,`salary`) VALUES ('天弘',20000) INSERT INTO `name_user` (`name`,`salary`) VALUES ('天弘',20000) INSERT INTO `name_user` (`name`,`salary`) VALUES ('天弘',20000) INSERT INTO `name_user` (`name`,`salary`) VALUES ('天弘',20000) INSERT INTO `name_user` (`name`,`salary`) VALUES ('天弘',20000) INSERT INTO `name_user` (`name`,`salary`) VALUES (`天弘`,20000) INSERT INTO `name_user` (`name`,`salary`) VALUES ('天弘',20000) INSERT INTO `name_user` (`name`,`salary`) VALUES ('天弘',20000) INSERT INTO `name_user` (`name`,`salary`) VALUES ('天弘',20000) */ // 在 name_user 表中 age 和 salary 字段进行修改 索引 id 为 1 的索引 UPDATE `name_user` SET `age`=28, `salary`=100000 WHERE `id`=1; /* UPDATE `name_user` SET `age`=28, `salary`=100000 WHERE `id`=1; UPDATE `name_user` SET `age`=28, `salary`=100000 WHERE `id`=1; UPDATE `name_user` SET `age`=28, `salary`=100000 WHERE `id`=1; UPDATE `name_user` SET `age`=28, `salary`=100000 WHERE `id`=1; UPDATE `name_user` SET `age`=28, `salary`=100000 WHERE `id`=1; UPDATE `name_user` SET `age`=28, `salary`=100000 WHERE `id`=1; UPDATE `name_user` SET `age`=28, `salary`=100000 WHERE `id`=1; UPDATE `name_user` SET `age`=28, `salary`=100000 WHERE `id`=1; UPDATE `name_user` SET `AGE`=28, `salary`=100000 WHERE `id`=1; */ // 查询 name_user 表中的所有的数据 SELECT * FROM `name_user`; /* SELECT * FROM `name_user`; SELECT * FROM `name_user`; SELECT * FROM `name_user`; SELECT * FROM `name_user`; SELECT * FROM `name_user`; SELECT * FROM `name_user`; SELECT * FROM `name_user`; SELECT * FROM `name_user`; SELECT * FROM `name_user`; */ // 查询 name_user 表中的 id name salary 这三个字段的数据 SELECT `id`,`name`,`salary` FROM `name_user`; /* SELECT `id`,`name`,`salary` FROM `name_user`; SELECT `id`,`name`,`salary` FROM `name_user`; SELECT `id`,`name`,`salary` FROM `name_user`; SELECT `id`,`name`,`salary` FROM `name_user`; SELECT `id`,`name`,`salary` FROM `name_user`; SELECT `id`,`name`,`salary` FROM `name_user`; SELECT `id`,`name`,`salary` FROM `name_user`; SELECT `id`,`name`,`salary` FROM `name_user`; SELECT `id`,`name`,`salary` FROM `name_user`; SELECT `id`,`name`,`salary` FROM `name_user`; */ // 查询 name_user 表中的 id name salary 这三个字段的数据,并且 salary 字段的值小于 10000的数据 SELECT `id`,`name`,`salary` FROM `name_user` WHERE `salary`<10000; /* SELECT `id`,`name`,`salary` FROM `name_user` WHERE `salary`<10000; SELECT `id`,`name`,`salary` FROM `name_user` WHERE `salary`<10000; SELECT `id`,`name`,`salary` FROM `name_user` WHERE `salary`<10000; SELECT `id`,`name`,`salary` FROM `name_user` WHERE `salary`<10000; SELECT `id`,`name`,`salary` FROM `name_user` WHERE `salary`<10000; SELECT `id`,`name`,`salary` FROM `name_user` WHERE `salary`<10000; SELECT `id`,`name`,`salary` FROM `name_user` WHERE `salary`<10000; SELECT `id`,`name`,`salary` FROM `name_user` WHERE `salary`<10000; SELECT `id`,`name`,`salary` FROM `name_user` WHERE `salary`<10000; */ // 查询 name_user 表中的有多少个字段 SELECT COUNT(*) FROM `name_user`; /* SELECT COUNT(*) FROM `name_user`; SELECT COUNT(*) FROM `name_user`; SELECT COUNT(*) FROM `name_user`; SELECT COUNT(*) FROM `name_user`; SELECT COUNT(*) FROM `name_user`; SELECT COUNT(*) FROM `name_user`; SELECT COUNT(*) FROM `name_user`; SELECT COUNT(*) FROM `name_user`; SELECT COUNT(*) FROM `name_user`; */ // 查询 name_user 表中的有多少个字段,并且别名为 RES SELECT COUNT(*) AS RES FROM `name_user`; /* SELECT COUNT(*) AS RES FROM `name_user`; SELECT COUNT(*) AS RES FROM `name_user`; SELECT COUNT(*) AS RES FROM `name_user`; SELECT COUNT(*) AS RES FROM `name_user`; SELECT COUNT(*) AS RES FROM `name_user`; SELECT COUNT(*) AS RES FROM `name_user`; SELECT COUNT(*) AS RES FROM `name_user`; SELECT COUNT(*) AS RES FROM `name_user`; SELECT COUNT(*) AS RES FROM `name_user`; */ // 删除 name_user 表中的 字段 id 为 1 的数据 DELETE FROM `name_user` WHERE `id`=1 /* DELETE FROM `name_user` WHERE `id`=1 DELETE FROM `name_user` WHERE `id`=1 DELETE FROM `name_user` WHERE `id`=1 DELETE FROM `name_user` WHERE `id`=1 DELETE FROM `name_user` WHERE `id`=1 DELETE FROM `name_user` WHERE `id`=1 DELETE FROM `name_user` WHERE `id`=1 DELETE FROM `name_user` WHERE `id`=1 DELETE FROM `name_user` WHERE `id`=1 */
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5、与MySQLil连接相关属性和方法的名称,参数,与功能和用法: