PHP第课：1. 抽象类 2. 接口 3、Db封装 11月29日

1、抽象类

<?php
//抽象类
abstract class a
{
    public  $name;
    public function  __construct($name)
    {
        $this->name = $name;
    }
    public function af()
    {
        echo $this->name.'111';
    }
//    这个方法是抽象方法
    abstract  public function aff();
}
class b extends a
{
    //必须重写这个方法
    public function aff()
    {
        echo $this->name.'222';
    }
}
$b = new b('欧阳克');
echo $b->aff();
abstract class Person
{
    protected $name;
    protected function __construct($name)
    {
        $this->name =$name;
    }
    public  function getName($name='欧阳克')
    {
        return $this->name;
    }
        abstract protected function setName($v);
}
class Stu extends Person {
    public  function __construct($name='欧阳克')
    {
        parent::__construct($name);
    }
    public function setName($v)
    {
        $this->name = $v;
    }
}
$s = new Stu('诸葛亮');
//echo 'PHP中文网创始人'.$s->getName();
$s -> setName('朱老师');
echo 'php中文网前段讲师:'. $s->getName();

2、接口

<?php
//接口
//必须全部是抽象方法
interface V
{
    const  LXR = '欧阳克';
    public function setFuel($fuel);
    public function setPurpose($purpose);
}
abstract class Auro implements V{
    public $fuel;
    public function setFuel($fuel)
    {
        $this->fuel = $fuel;
    }
}
class Car implements V{
    public  $fuel;
    public  $purpose;
    public function __construct($purpose,$fuel)
    {
        $this->purpose =$purpose;
        $this->fuel =$fuel;
    }
    public function setFuel($fuel)
    {
    $this->fuel = $fuel;
    }
    public function setPurpose($purpose)
    {
        $this->purpose = $purpose;
    }
    public function getInfo()
    {
        return $this->fuel.$this->purpose;
    }
}
$ks = new  Car('电动车','公交');
echo $ks ->getInfo('zhu');

3、上次的作业继续继续完成 封装Db类

<?php
//公共方法库
class Db
{
    protected $table = null;
    protected  $pdo;
    public function __construct($dsn,$user,$password,$table)
    {
        $this->pdo = new PDO($dsn,$user,$password);
        $this->table = $table;
    }
//    查询方法
    //select * from biao WHERE 条件 order by 排序 limit 页
    public function select($where='',$order='',$limilt='0,10', $filed='*')
    {
        //select from 必须有
        $sql = 'SELECT ';
        if($filed == '*'){
            $sql .= '* FROM ';
        } else{
            $sql .= $filed.' FROM ';
        }
        $sql .= $this->table;
        if(!$where){
            $sql .= ' WHERE '.$where;
        }
        print_r($sql);
        if($order)
        {
            $sql .= ' ORDER BY '.$order;
        }
        print_r($sql);
        $stmt = $this->pdo->prepare($sql);
        if($stmt->execute())
        {
            if($stmt->rowCount()>0){
                $stmt->setFetchMode(PDO::FETCH_ASSOC);
                return $stmt->fetchAll();
            }
        }else {
            return false;
        }
        $sql = 'SELECT FROM';
    }
    //插入数据
    public function insert($table,$data)
    {
        $sql = "INSERT INTO `{$table}` SET ";
        //组装插入语句
        if(is_array($data)){
            foreach ($data as $k=>$v) {
                $sql .= $k.'="'.$v.'", ';
            }
        }else{
            return false;
        }
//        print_r($sql);
        //去掉尾部逗号,并添加分号结束
        $sql = rtrim(trim($sql),',').';';
        //创建PDO预处理对象
//        print_r($sql);
        $stmt = $this->pdo->prepare($sql);
        //执行新增操作
//      print_r($stmt);
        if($stmt->execute()){
            if($stmt->rowCount()>0){
                $num = $stmt->rowCount();
                if($num){
                    $id = $this->pdo->lastInsertId();
                    echo "<h3>成功新增 {$num}了条记录.新增记录的主键id:{$id}</h3>";
                }
                }
        } else {
            return false;
        }
//        print_r($stmt);
        }
//    更新操作
    function update($table,$data,$where='') {
        //创建SQL语句
        $sql = "UPDATE `{$table}` SET ";
        //组装修改语句
        if(is_array($data)){
            foreach ($data as $k=>$v) {
                $sql .= $k.'="'.$v.'", ';
            }
        }
//        print_r($sql);
        //去掉尾部逗号,并添加分号结束
        $sql = rtrim(trim($sql),',');
        //查询条件
        if(!empty($where)){
            $sql .= ' WHERE '.$where;
        }
//        print_r($sql);
        //创建PDO预处理对象
        $stmt = $this->pdo->prepare($sql);
        //执行新增操作
        if($stmt->execute()){
            if($stmt->rowCount()>0){
                $num = $stmt->rowCount();
                if($num){
                    $id = $this->pdo->lastInsertId();
                    echo "<h3>成功更新 {$num}了条记录</h3>";
                }
            }
        } else {
            return false;
        }
    }
    public function delete($table,$where){
        // 预处理执行删除操作
        $sql = 'DELETE FROM '.$table.' WHERE '.$where;
        $stmt = $this->pdo->prepare($sql);
        $stmt->execute();
        return $stmt->rowCount();
    }
}
//实例化对象 并向 构造方法传参
$a = new Db('mysql:host=127.0.0.1;dbname=pdo','root','root','users');
////查询方法 查询多个记录
//$selects = $a->select('id=4 AND id = 11','age DESC','0,10','id,username,password');
//
//print_r($selects);
////插入数据 单条
//$insert = $a->insert('users',['username'=>'张三','password'=>sha1('123456'),'age'=>35]);
//print_r($insert);
//
//$update = $a ->update('users',['username'=>'老黄','password'=>sha1(123456),'age'=>'18'],"id=153");
//print_r($update);
// 删除记录
$where = 'id >= 150';
echo '成功删除了: ' .$a->delete('users',$where). ' 条记录';