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PHP method to implement database addition, deletion, modification and query

墨辰丷

May 25, 2018 pm 02:08 PM

php database method

This article introduces to you the methods and sample codes for connecting to the database with PHP and implementing the add, delete, modify and query functions of the database. I hope it will be helpful for everyone to learn PHP

1. Query :

Data display, here you can embed php for data output

<!DOCTYPE html>
<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  <title>无标题文档</title>
</head>

<body>
<table width="100%" border="1" cellpadding="0" cellspacing="0">
  <tr>
    <td>代号</td>
    <td>名称</td>
    <td>性别</td>
    <td>生日</td>
    <td>班级</td>
    <td>操作</td>
  </tr>

<?php
$db = new MySQLi("localhost","root","12345678","heiheihei");
//连接数据库
$sql = "select * from student ";
//写sql语句
$r = $db->query($sql);
//执行sql语句返回给r
if($r)//条件
{
  while ($attr = $r->fetch_row())
  {
    $ssex = "";
     if($attr[2])
     {
       $ssex = "男";
     }
     else
       {
         $ssex = "女";
       }
    echo
    "
 <tr>
    <td>{$attr[0]}</td>
    <td>{$attr[1]}</td>
    <td>{$ssex}</td>
    <td>{$attr[3]}</td>
    <td>{$attr[4]}</td>
//添加一个单击事件，防止不小心删掉
<td><a onclick=\"return confirm(&#39;确定要删除吗？？？&#39;)" 
href=&#39;shanchu.php?sno={$attr[0]}&#39;>删除</a>
 <a href=&#39;xiugai.php?sno={$attr[0]}&#39;>修改</a> </td> </tr>"; } } ?>

 
 

</table>
<a href="tianjia.php" rel="external nofollow" >添加页面</a>
</body>

</html>

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2. Deletion processing page

When deleting, it is linked to the deletion processing page, so a deletion processing page must be written:

<?php
$aaa = $_GET ["sno"]; //删除方式使用的get，照旧
$db = new mysqli("localhost","root","12345678","heiheihei");
//连接...
$sql = "delete from student WHERE sno=&#39;{$aaa}&#39;";
//写sql语句，sno主键
if($db->query($sql)) //执行sql语句
{
  header("location:text.php");
//删完回去表页面
}
else{
  echo "删除失败";
}
?>

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Here is a rendering:

3 .Add data:

Click to enter the add page

Add page:

<body>

<h1>添加</h1>
<form action="add.php" method="post" >
  <p>代号:<input type="text" name="sno"/></p>
  <p>名字:<input type="text" name="sname"/></p>
  <p>性别: <input type="radio" value="1" name="sex" />男
    <input type="radio" value="0" name="sex"/>女</p>
  <p>日期:<input type="text" name="sbirthday"/></p>
//创建表时性别是用的1或2来表示的，要是进行修改不知道1或2代表了什么，所以就要进行处理，处理成用户能够明白的男和女

  <p>班级:
  <select name="class">

  <?php
    $db= new MYSQLi("localhost","root","12345678","heiheihei");
//连接...
    $sql = " select * from class ";
//写sql...    

    $r = $db->query($sql);
//执行...返回...
    while($arr = $r->fetch_row())
    {
      echo "<option value=&#39;{$arr[0]}&#39;>{$arr[1]}</option>";
      //添上以后回表页面
    }
    ?>

 
  </select>
  </p>
  <p><input type="submit" value="添加"/></p>
</form>

</body>

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Adding also requires a processing page to determine the addition:

<?php
$sno = $_POST["sno"];
//$_POST 变量用于收集来自 method="post" 的表单中的值。
$sname = $_POST["sname"];
$ssex = $_POST["ssex"];
$sbirthday = $_POST["sbirthday"];
$class = $_POST["class"];
$db = new mysqli("localhost","root","12345678","heiheihei");
$sql = "insert into student VALUES (&#39;{$sno}&#39;,&#39;{$sname}&#39;,&#39;{$ssex}&#39;,&#39;{$sbirthday}&#39;,&#39;{$class}&#39;)";
//向数据库中添加写的数据
  if($db->query($sql))
{
  header("location:text.php");
  //header() 函数向客户端发送原始的 HTTP 报头。
}
else {
  echo "添加失败";
}


?>

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##Rendering:

4. Modify data: The primary key cannot be modified! !

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  <title>无标题文档</title>
</head>

<body>

<h1>修改</h1>

<?php
$sno = $_GET{"sno"};
$db = new mysqli("localhost","root","12345678","heiheihei");
$sql = "select * from student WHERE sno=&#39;{$sno}&#39;";
$r = $db->query($sql);
$arr = $r->fetch_row();
?>

 
<form action="update.php" method="post">
  <p>代号：<input readonly="readonly" type="text" name="sno" value="<?php
echo $arr[0];
?>"/></p>

//readonly只可读
 <p>名称：<input type="text" name="sname" value="<?php echo $arr[1]; ?>"/></p> <p>性别： <input type="radio" name="ssex" value="1" <?php echo $arr[2]?"checked=&#39;checked&#39;":""; ?>/>男 <!-- 三元运算符，如果性别=ture，默认值就在男上面，否则空--> <input type="radio" name="ssex" value="0" <?php echo $arr[2]?"":"checked=&#39;checked&#39;"; ?>/>女 </p> <p>日期：<input type="text" name="sbirthday" value="<?php echo $arr[3]; ?>"/></p> <p>班级：<select name="class">
//value取默认值
 

 <?php
      $sclass = "select * from class";
      $rclass = $db->query($sclass);
      while($attr = $rclass->fetch_row())
      //取到的班级信息
      {
        //判断将要输出的班级是不是和该人员的是否相同
        if($arr[4]==$attr[0])//arr是班级名，attr是班级的代号，俩表
        {
          echo "<option value = &#39;{$attr[0]}&#39; selected=&#39;selected&#39;>{$attr[1]}</option>";

        }
        else{
          echo "<option value = &#39;{$attr[0]}&#39;>{$attr[1]}</option>";
        }

      }
      ?>

 
    </select></p>
  <p><input type="submit" value="修改完毕"/></p>

</form>


</body>
</html>

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]

Modified processing page:

<?php
$sno = $_POST["sno"];
$sname = $_POST["sname"];
$ssex = $_POST["ssex"];
$sbirthday = $_POST["sbirthday"];
$class = $_POST["class"];
$db = new mysqli("localhost","root","12345678","heiheihei");
$sql = "update student set sname=&#39;{$sname}&#39;,
ssex=&#39;{$ssex}&#39;,
sbirthday=&#39;{$sbirthday}&#39;,
class=&#39;{$class}&#39; WHERE sno=&#39;{$sno}&#39;";
//看一下是不是传递过来的sno值；
if($db->query($sql))
{
  header("location:text.php");
}
else{
  echo "修改失败";
}



?>

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Modified renderings:

The above is the entire content of this article, I hope it will be helpful to Everyone’s learning helps.

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