11月26日作业数据库操作函数重写到 Db类中--PHP培训九期线上班

用到两个文件

connect.php数据库链接相关的文件

<?php
class con{
//    需要用到的属性
    public $host;
    public $user;
    public $pass;
    public $name;
    public $type;
    public $port;
    public $charset;
    public $dsn;
//    创建链接数据库的方法construct
public function construct($host,$user,$pass,$name,$type='mysql',$port=3306,$charset='utf8' ){
    $this->host=$host;
    $this->user=$user;
    $this->pass=$pass;
    $this->name=$name;
    $this->type=$type;
    $this->port=$port;
    $this->charset=$charset;
    $db = array(
        'charset' => $this->charset,
        'port' => $this->port,
        'type' => $this->type,
        'host' => $this->host,
        'user' => $this->user,
        'pass' => $this->pass,
        'name' => $this->name
    );
    $dsn = "{$db['type']}:host={$db['host']}; dbname={$db['name']}; charset={$db['charset']}; port={$db['port']}";//数据源
    try {
        //实例化PDO类,创建PDO对象
        $pdo = new PDO($dsn,$db['user'],$db['pass']);
    } catch (PDOException $e) {
        die('数据库错误:'.$e->getMessage());
    }
    return $pdo;
}
}
//实例化父类的对象
$c1=new con();
//     链接数据库
$pdo=$c1->construct('127.0.0.1','root','root','dedecmsv57');

pdoclass.php文件

<?php
//引入connect数据库链接文件中的con类
require __DIR__.'/connect.php';
//创建con的子类find
class find extends con{
public $table;
public $fields;
public $where;
public $order;
public $limit;
//创建子类的查询find
 public   function select($table,$fields, $where='', $order='',$limit=''){
    $this->table = $table;
    $this->fields=$fields;
    $this->where=$where;
    $this->order=$order;
    $this->limit=$limit;
     //实例化父类的对象
     $c1=new con();
//     链接数据库
     $pdo=$c1->construct('127.0.0.1','root','root','dedecmsv57');
        //创建SQL语句
        $sql = 'SELECT ';
        if (is_array($fields)) {
            foreach ($fields as $field) {
                $sql .= $field.', ';
            }
        } else {
            $sql .= $fields;
        }
        $sql = rtrim(trim($sql),',');
        $sql .= '  FROM '.$table;
        //查询条件
        if(!empty($where)){
            $sql .= ' WHERE '.$where;
        }
        //排序条件
        if(!empty($order)) {
            $sql .= ' order by '.$order;
        }
        //分页条件
        if(!empty($limit)) {
            $sql .= ' limit '.$limit;
        }
        $sql .= ';';
        //创建PDO预处理对象
        $stmt = $pdo->prepare($sql);
        //执行查询操作
        if($stmt->execute()){
            if($stmt->rowCount()>0){
                $stmt->setFetchMode(PDO::FETCH_ASSOC);
                //返回一个二维数组
                return $stmt->fetchAll();
            }
        } else {
            return false;
        }
    }
//    查询单条记录
public function find2($table,$fields,$where=''){
    //实例化父类的对象
    $c1=new con();
//     链接数据库
    $pdo=$c1->construct('127.0.0.1','root','root','dedecmsv57');
    $sql = 'SELECT ';
    if (is_array($fields)) {
        foreach ($fields as $field) {
            $sql .= $field.', ';
        }
    } else {
        $sql .= $fields;
    }
    $sql = rtrim(trim($sql),',');
    $sql .= ' FROM '.$table;
    //查询条件
    if(!empty($where)){
        $sql .= ' WHERE '.$where;
    }
    $sql .= ' LIMIT 1;';
    //创建PDO预处理对象
    $stmt = $pdo->prepare($sql);
    //执行查询操作
    if($stmt->execute()){
        if($stmt->rowCount()>0){
            $stmt->setFetchMode(PDO::FETCH_ASSOC);
            return $stmt->fetch();
        }
    } else {
        return false;
    }
}
//* 新增数据
public function insert($table,$data=[]){
    //实例化父类的对象
    $c1=new con();
//     链接数据库
    $pdo=$c1->construct('127.0.0.1','root','root','dedecmsv57');
    $sql = "INSERT INTO {$table} SET ";
    //组装插入语句
    if(is_array($data)){
        foreach ($data as $k=>$v) {
            $sql .= $k.'="'.$v.'", ';
        }
    }else{
        return false;
    }
    //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
    $stmt = $pdo->prepare($sql);
    //执行新增操作
    if($stmt->execute()){
        if($stmt->rowCount()>0){
            return true;
        }
    } else {
        return false;
    }
}
//* 统计数量
public function count_num($table,$where=''){
    //实例化父类的对象
    $c1=new con();
//     链接数据库
    $pdo=$c1->construct('127.0.0.1','root','root','dedecmsv57');
    $sql  = 'SELECT count(*) as count_number FROM '.$table;
    //查询条件
    if(!empty($where)){
        $sql .= ' WHERE '.$where;
    }
    //创建PDO预处理对象
    $stmt = $pdo->prepare($sql);
    //执行查询操作
    if($stmt->execute()){
        if($stmt->rowCount()>0){
            $row  = $stmt->fetch(PDO::FETCH_ASSOC);
            $rows = $row['count_number'];
            return $rows;
        }
    } else {
        return false;
    }
}
}
//实例化对象
 $s1=new find();
//查询到的数据是一个二维数组
$find1=$s1->select('dede_addonarticle','aid,typeid,userip,body');
//输出二维数组的body字段
foreach ($find1 as $v){
        echo $v['userip'].'<br>';
        echo $v['body'].'<br>';
}
//    查询单条记录
$value=$s1->find2('dede_addonarticle','aid,typeid,userip,body');
echo $value['body'];
//* 更新数据
$s1->insert('dede_addonarticle','[1,20,"body里的文章内容比较多","我也不知道这是啥","这也不知道","2"]');
//* 统计数量
$a=$s1->count_num('dede_addonarticle');
echo $a;

以上方法都能运行出来