PHP uses the mysqli extension library to implement addition, deletion, modification and query (object-oriented version)

<?<span style="color: #000000;">php
 </span><span style="color: #008000;">//</span><span style="color: #008000;">数据库操作类</span>
  <span style="color: #0000ff;">class</span><span style="color: #000000;"> DBUtil{
   </span><span style="color: #0000ff;">private</span> <span style="color: #800080;">$host</span>="localhost"<span style="color: #000000;">;
   </span><span style="color: #0000ff;">private</span> <span style="color: #800080;">$username</span>="root"<span style="color: #000000;">;
   </span><span style="color: #0000ff;">private</span> <span style="color: #800080;">$password</span>="123456"<span style="color: #000000;">;
   </span><span style="color: #0000ff;">private</span> <span style="color: #800080;">$dbname</span>="student"<span style="color: #000000;">;
   </span><span style="color: #0000ff;">private</span> <span style="color: #800080;">$conn</span><span style="color: #000000;">;
   </span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> DBUtil(){
     </span><span style="color: #800080;">$this</span>->conn=<span style="color: #0000ff;">new</span> mysqli(<span style="color: #800080;">$this</span>->host, <span style="color: #800080;">$this</span>->username, <span style="color: #800080;">$this</span>->password,<span style="color: #800080;">$this</span>->dbname) or <span style="color: #0000ff;">die</span>(<span style="color: #800080;">$this</span>->conn-><span style="color: #000000;">connect_error);
    
   }
  </span><span style="color: #008000;">//</span><span style="color: #008000;">查询</span>
   <span style="color: #0000ff;">public</span> <span style="color: #0000ff;">function</span> query(<span style="color: #800080;">$sql</span><span style="color: #000000;">){
     </span><span style="color: #800080;">$all</span>= <span style="color: #800080;">$this</span>->conn->query(<span style="color: #800080;">$sql</span><span style="color: #000000;">);
     </span><span style="color: #0000ff;">return</span> <span style="color: #800080;">$all</span><span style="color: #000000;">;
   }
  </span><span style="color: #008000;">//</span><span style="color: #008000;">插入,修改，删除</span>
   <span style="color: #0000ff;">public</span> <span style="color: #0000ff;">function</span> otherOperate(<span style="color: #800080;">$sql</span><span style="color: #000000;">){
      </span><span style="color: #0000ff;">if</span>(<span style="color: #800080;">$this</span>->conn->query(<span style="color: #800080;">$sql</span><span style="color: #000000;">)){
        </span><span style="color: #0000ff;">if</span>(<span style="color: #800080;">$this</span>->conn->affected_rows>0<span style="color: #000000;">){
           </span><span style="color: #0000ff;">return</span> "OK"<span style="color: #000000;">;
        }</span><span style="color: #0000ff;">else</span><span style="color: #000000;">{
           </span><span style="color: #0000ff;">return</span> "ERROOR"<span style="color: #000000;">;
        }
      }
   }
   </span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">function</span><span style="color: #000000;"> close(){
     </span><span style="color: #800080;">$this</span>->conn-><span style="color: #000000;">close();
   }
  }
</span>?>

<?<span style="color: #000000;">php
  </span><span style="color: #0000ff;">require_once</span> "MySQLUtil.php"<span style="color: #000000;">;
   </span><span style="color: #008000;">/*</span><span style="color: #008000;">$sql="select * from m_student";
   $util=new DBUtil();
   $result=$util->query($sql);
   while($row=$result->fetch_assoc()){
        echo "$row[stuName]"."</br>";
   }
   $result->free();
   $util->close();<span style="color: #008000;">*/</span>
   <span style="color: #800080;">$sql</span>="update m_student set stuName='杨幂' where id=3"<span style="color: #000000;">;
   </span><span style="color: #800080;">$util</span>=<span style="color: #0000ff;">new</span><span style="color: #000000;"> DBUtil();
   </span><span style="color: #800080;">$result</span>=<span style="color: #800080;">$util</span>->otherOperate(<span style="color: #800080;">$sql</span><span style="color: #000000;">);
   </span><span style="color: #0000ff;">echo</span> <span style="color: #800080;">$result</span><span style="color: #000000;">;
   </span><span style="color: #800080;">$util</span>-><span style="color: #000000;">close();
</span>?>