PHPオブジェクト指向データベース接続で追加、削除、変更を実装する方法

<?php
    class
 Mysql{
        private
 $host;//服务器地址
        private
 $root;//用户名
        private
 $password;//密码
        private
 $database;//数据库名
         
        //后面所提到的各个方法都放在这个类里
        //...
    }
?>

function
 __construct($host,$root,$password,$database){
    $this->host
 = $host;
    $this->root
 = $root;
    $this->password
 = $password;
    $this->database
 = $database;
    $this->connect();
}

function
 connect(){
    $this->conn
 = mysql_connect($this->host,$this->root,$this->password) or die("DB
 Connnection Error !".mysql_error());
    mysql_select_db($this->database,$this->conn);
    mysql_query("set
 names utf8");
}
         
function
 dbClose(){
    mysql_close($this->conn);
}

function
 query($sql){
    return
 mysql_query($sql);
}
        
function
 myArray($result){
    return
 mysql_fetch_array($result);
}
        
function
 rows($result){
    return
 mysql_num_rows($result);
}

function
 select($tableName,$condition){
    return
 $this->query("SELECT
 * FROM $tableName $condition");
}

function
 insert($tableName,$fields,$value){
    $this->query("INSERT
 INTO $tableName $fields VALUES$value");
}

function
 update($tableName,$change,$condition){
    $this->query("UPDATE
 $tableName SET $change $condition");
}

function
 delete($tableName,$condition){
    $this->query("DELETE
 FROM $tableName $condition");
}

$db
 = new Mysql("localhost","root","admin","beyondweb_test");

<?php
    require("mysql_class.php");
?>

<?php
    $insert
 = $db->insert("user","(nikename,email)","(#beyondweb#,#beyondwebcn@xx.com#)");//请把#号替换为单引号
    $db->dbClose();
?>

<?php
    $update
 = $db->update("user","nikename
 = #beyondwebcn#","where
 id = #2#");//请把#号替换为单引号
    $db->dbClose();
?>

<?php
    $select
 = $db->select("user");
    $row
 = $db->rows($select);
    if($row>=1){
?>
<table
 border="1px">
    <tr>
        <th>id</th>
        <th>nikename</th>
        <th>email</th>
    </tr>
<?php
    while($array
 = $db->myArray($select)){
        echo
"<tr>";
        echo
"<td>".$array[#id#]."</td>";//请把#号替换为单引号
        echo
"<td>".$array[#nikename#]."</td>";//请把#号替换为单引号
        echo
"<td>".$array[#email#]."</td>";//请把#号替换为单引号
        echo
"</tr>";
    }
?>
</table>
<?php
    }else{
        echo
"查不到任何数据!";
    }
      
    $db->dbClose();
?>

<?php
    $delete
 = $db->delete("user","where
 nikename = #beyondweb#");//请把#号替换为单引号
    $db->dbClose();
?>