php页面中实现对数据库的操作

<?php
//var_dump($_POST);

$title = $_POST["title"];
$Author = $_POST["Author"];
$source = $_POST["source"];
$content = $_POST["content"];
$time = time();

$db = new MySQLi("localhost","root","123","newssystem");
$sql = "insert into news values(0,‘{$title}‘,‘{$Author}‘,‘{$source}‘,‘{$content}‘,now())";
echo $sql;
$result = $db->query($sql);

if($result){
    echo "<script type=‘text/javascript‘>window.location.href=‘fabuxinwen.php‘;</script>";
}else{
    echo "添加失败！";
}

//首先在页面内添加一个表格，并设置列名
<table class="table table-bordered">
  <thead>
    <tr>
      <th>id</th>
      <th>title</th>
      <th>author</th>
      <th>source</th>
      <th>date</th>
      <th>update</th>
      <th>delete</th>
    </tr>
  </thead>
//表身内容为数据库存储的内容，对其进行展示
  <tbody>
     <?php
    $db = new MySQLi("localhost","root","123","newssystem");
    $sql = "select * from news";
    $result = $db->query($sql);
    if($result){
        $arr = $result->fetch_all();
        foreach($arr as $v){
            echo "<tr>
      <td>{$v[0]}</td>
      <td>{$v[1]}</td>
      <td>{$v[2]}</td>
      <td>{$v[3]}</td>
      <td>{$v[5]}</td>
      <td>
          <a href=‘xiugai.php?newsid={$v[0]}‘ ><button type=‘button‘ class=‘btn btn-primary btn-sm‘>修改</button></a>
      </td>
      <td>
          <a href=‘shanchu.php?title={$v[1]}‘ onclick=\"return confirm(‘确认删除么？‘)\">
　　　　　　　　<button type=‘button‘ class=‘btn btn-primary btn-sm‘>删除</button>
　　　　　　</a>
      </td>
    </tr>";
        }
    }
    ?>
  </tbody>
</table>

<?php
$title = $_GET["title"];
$db = new MySQLi("localhost","root","123","newssystem");
$sql = "delete from news where title=‘{$title}‘";
$result = $db->query($sql);
if($result){
    header("location:chakan.php");
}else{
    echo "删除失败！";
}

 <td><input type=‘checkbox‘ class=‘ck‘ name=‘ck[]‘ value=‘{$v[0]}‘/>{$v[0]}</td>

<input type="checkbox" id="ckall" />

<script type="text/javascript">
var ckall = document.getElementById("ckall");
ckall.onclick = function(){
    var xz = ckall.checked;
    var ck = document.getElementsByClassName("ck");
    for(var i=0;i<ck.length;i++){
        ck[i].checked = xz; 
    }
}
</script>

<?php
$arr = $_POST["ck"];

//delete from info where code in(‘p001‘,‘p002‘,‘p003‘)

$str = implode("‘,‘",$arr);
$sql = "delete from info where code in(‘{$str}‘)";

$db = new MySQLi("localhost","root","123","mydb");
$result = $db->query($sql);
if($result){
    header("location:main.php");
}else{
    echo "删除失败！";
}

//在要展示的修改的页面加入一段php代码
<?php
//取出主键值
$newsid = $_GET["newsid"];
//读取该条数据
$db = new MySQLi("localhost","root","123","newssystem");
$sql = "select * from news where newsid={$newsid}";
$result = $db->query($sql);
$arr1 = $result->fetch_row();
?>

<?php
$newsid = $_POST["newsid"];
$title = $_POST["title"];
$Author = $_POST["Author"];
$source = $_POST["source"];
$content = $_POST["content"];

$db = new MySQLi("localhost","root","123","newssystem");
$sql = "update news set title=‘{$title}‘,Author=‘{$Author}‘,source=‘{$source}‘,content=‘{$content}‘ where newsid = {$newsid}";

$result = $db->query($sql);
if($result){
    header("location:chakan.php");
}else{
    echo "修改失败！";
}