php实现数据库的增删改查
(编辑：jimmy 日期: 2024/5/10 浏览：3 次 )
1.查询：
数据的显示，这里就可以嵌入php来进行数据的输出
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<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>
<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>
<"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('确定要删除吗？？？')"
href='shanchu.php"; } } "tianjia.php" rel="external nofollow" >添加页面</a>
</body>
</html>
2.删除的处理页面
删除时是链接到删除处理页面的，所以还要写一个删除处理页面：
<"sno"]; //删除方式使用的get，照旧
$db = new mysqli("localhost","root","12345678","heiheihei");
//连接...
$sql = "delete from student WHERE sno='{$aaa}'";
//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";
}
"" src="/UploadFiles/2021-04-02/2017022615192211.png">
3.添加数据：
点击
即可进入添加页面
添加页面：
<body>
<h1>添加</h1>
<form action="add.php" method="post" >
<div>代号:<input type="text" name="sno"/></div>
<div>名字:<input type="text" name="sname"/></div>
<div>性别: <input type="radio" value="1" name="sex" />男
<input type="radio" value="0" name="sex"/>女</div>
<div>日期:<input type="text" name="sbirthday"/></div>
//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
<div>班级:
<select name="class">
<"localhost","root","12345678","heiheihei");
//连接...
$sql = " select * from class ";
//写sql...
$r = $db->query($sql);
//执行...返回...
while($arr = $r->fetch_row())
{
echo "<option value='{$arr[0]}'>{$arr[1]}</option>";
//添上以后回表页面
}
"submit" value="添加"/></div>
</form>
</body>
添加也需要一个处理页面来判断添加：
<"sno"];
//$_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");
$sql = "insert into student VALUES ('{$sno}','{$sname}','{$ssex}','{$sbirthday}','{$class}')";
//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";
}
"" src="/UploadFiles/2021-04-02/2017022615192213.png">
4.修改数据：主键不可修改！！
<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>
<"sno"};
$db = new mysqli("localhost","root","12345678","heiheihei");
$sql = "select * from student WHERE sno='{$sno}'";
$r = $db->query($sql);
$arr = $r->fetch_row();
"update.php" method="post">
<div>代号：<input readonly="readonly" type="text" name="sno" value="<"/></div>
//readonly只可读
<div>名称：<input type="text" name="sname" value="<"/></div> <div>性别： <input type="radio" name="ssex" value="1" <"checked='checked'":""; "radio" name="ssex" value="0" <"":"checked='checked'"; "text" name="sbirthday" value="<"/></div> <div>班级：<select name="class">
//value取默认值
<"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]==$attr[0])//arr是班级名，attr是班级的代号，俩表
{
echo "<option value = '{$attr[0]}' selected='selected'>{$attr[1]}</option>";
}
else{
echo "<option value = '{$attr[0]}'>{$attr[1]}</option>";
}
}
"submit" value="修改完毕"/></div>
</form>
</body>
</html>
]
修改的处理页面：
<"sno"];
$sname = $_POST["sname"];
$ssex = $_POST["ssex"];
$sbirthday = $_POST["sbirthday"];
$class = $_POST["class"];
$db = new mysqli("localhost","root","12345678","heiheihei");
$sql = "update student set sname='{$sname}',
ssex='{$ssex}',
sbirthday='{$sbirthday}',
class='{$class}' WHERE sno='{$sno}'";
//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";
}
"" src="/UploadFiles/2021-04-02/2017022615192214.png">
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