数据访问例题
1.查询表中元素，性别显示男女，民族显示名称
</head>
<body>
<table width="100%" border="1" cellpadding="0" cellspacing="0">
<tr>
<td>代号</td>
<td>姓名</td>
<td>性别</td>
<td>民族</td>
<td>生日</td>
</tr>
<?php
//造对象
$db= new Mysqli("localhost","root","","aaas");
//判断是否出错
!mysqli_connect_error() or die("连接失败！");
//写SQL语句
$sql="select * from info";
//执行SQL语句
$result=$db->query($sql);
//读取数据
$attr=$result->fetch_all();
//遍历数组，显示
foreach($attr as $v)
{
$sex=$v[2]?"男":"女";
$sql="select name from nation where code='{$v[3]}'";
$r=$db->query($sql);
$a=$r->fetch_row();
echo "
<tr>
<td>{$v[0]}</td>
<td>{$v[1]}</td>
<td>{$sex}</td>
<td>{$a[0]}</td>
<td>{$v[4]}</td>
</tr>
";
}
?>
</table>
2.添加数据
主页：
<!--##############################################添加数据##############################################-->
<h1>添加数据</h1>
<form action="0613addchuli.php" method="post">
<div>代号：<input type="text" name="code"></div>
<div>姓名：<input type="text" name="name"></div>
<div>性别：<input type="radio" value="1" name="sex">男
<input type="radio" value="0" name="sex">女
</div>
<div>民族：
<select name="nation">
<?php
$db=new Mysqli("localhost","root","","aaas");
!mysqli_connect_error() or die("连接错误！");
$sql="select * from nation";
$result=$db->query($sql);
$attr=$result->fetch_all();
foreach($attr as $v)
{
echo "<option value='{$v[0]}'>{$v[1]}</option>";
}
?>
</select>
</div>
<div>生日：<input type="text" name="birthday"></div>
<input type="submit" value="添加">
</form>
<a>返回主页面</a>
"0613addchuli.php"代码
<?php
$code=$_POST["code"];
$name=$_POST["name"];
$sex=$_POST["sex"];
$nation=$_POST["nation"];
$birthday=$_POST["birthday"];
$s=$sex==1?'true':'false';//没必要处理
//造对象
$db=new mysqli("localhost","root","","aaas");
//判断连接是否正确
!mysqli_connect_error() or die("链接失败！");
//写SQL语句
$sql="insert into info values('{$code}','{$name}',{$s},'{$nation}','{$birthday}')";//$s属于bool型，不要加单引号
//执行SQL语句
$r=$db->query($sql);
if($r)
{
header("location:0613chaxun.php");
}
else{
echo "添加失败！";
}
3.删除数据
<!--#######################删除表中元素#######################-->
<table width="100%" border="1" cellspacing="0" cellpading="0">
<tr>
<td>代号</td>
<td>姓名</td>
<td>性别</td>
<td>民族</td>
<td>生日</td>
<td>操作</td>
</tr>
<?PHP
//早对象那个
$db=new mysqli("localhost","root","","aaas");
//判断链接
!mysqli_connect_error() or die("链接错误！");
//SQL语句
$sql="select * from info";
//执行SQL语句
$result=$db->query($sql);
//读取数据
$attr=$result->fetch_all();
foreach($attr as $v)
{
//性别显示男女$v[2]
$sex=$v[2]?"男":"女";
//判断民族 $v[3]
$sql1="select name from nation where code='$v[3]'";
$re=$db->query($sql1);
$a=$re->fetch_row();
echo "
<tr>
<td>{$v[0]}</td>
<td>{$v[1]}</td>
<td>{$sex}</td>
<td>{$a[0]}</td>
<td>{$v[4]}</td>
<td><a href='0613delete.php?code={$v[0]}'>删除</a></td>
</tr>
";
}
?>
</table>
0613delete.php代码
<?php
$code=$_GET["code"];
$db=new mysqli("localhost","root","","aaas");
!mysqli_connect_error () or die("了解失败！");
$sql="delete from info where code='{$code}'";
$r=$db->query($sql);
if ($r)
{
header("location:0612chaxun.php");
}
else{
echo "删除失败！";
}
4.修改数据
<!--#######################修改表中元素#######################-->
<table width="100%" border="1" cellpadding="0" cellspacing="0">
<tr>
<td>代号</td>
<td>姓名</td>
<td>性别</td>
<td>民族</td>
<td>生日</td>
<td>操作</td>
</tr>
<?php
//造对象
$d=new mysqli("localhost","root","","aaas");
//判断连接
!mysqli_connect_error()or die("链接失败！");
//构造SQL函数‘
$sql="select * from info";
//执行SOL函数
$result = $db->query($sql);
//读取数组
$attr=$result->fetch_all();
//遍历数组
foreach($attr as $v)
{
//性别显示男女
$sex=$v[2]?"男":"女";
//民族显示名字 $v[3]
$sql="select name from nation where code='$v[3]'";
$re=$db->query($sql);
$a=$re->fetch_row();
echo "
<tr>
<td>{$v[0]}</td>
<td>{$v[1]}</td>
<td>{$sex}</td>
<td>{$a[0]}</td>
<td>{$v[4]}</td>
<td><a href='0613update.php?code={$v[0]}'>修改</a></td>
</tr>
";
}
?>
</table>
0613update.php 代码
<!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>
<h1>修改数据</h1>
<?php
$code = $_GET["code"];
$db=new mysqli("localhost","root","","aaas");
$sql="select * from info where code='{$code}'";
$result=$db->query($sql);
$attr=$result->fetch_row();
?>
<form action="0613updatechuli.php" method="post">
<div>
代号：<input type="text" name="code" value="<?php echo $attr[0] ?>">
</div>
<div>
姓名：<input type="text" name="name" value="<?php echo $attr[1] ?>">
</div>
<div>
性别：<input type="radio" value="1" name="sex" <?php echo $attr[2]?"checked='checked'":"" ?>>男
<input type="radio" value="0" name="sex" <?php echo $attr[2]?"":"checked='checked'" ?>>女
</div>
<div>
民族：
<select name="nation">
<?php
$db=new Mysqli("localhost","root","","aaas");
!mysqli_connect_error() or die("连接错误！");
$sql="select * from nation";
$result=$db->query($sql);
$attr1=$result->fetch_all();
foreach($attr1 as $v)
{
//判断民族是否选中
if($attr[3] ==$v[0])
{
echo "<option selected='selected' value='{$v[0]}'>{$v[1]}</option>";
}
else
{
echo "<option value='{$v[0]}'>{$v[1]}</option>";
}
}
?>
</select>
</div>
<div>生日：<input type="text" name="birthday" value="<?php echo $attr[4] ?>"></div>
<input type="submit" value="添加">
</form>
<a>返回主页面</a>
0613updatechuli.php代码
<?php
$code=$_POST["code"];
$name=$_POST["name"];
$sex=$_POST["sex"];
$nation=$_POST["nation"];
$birthday=$_POST["birthday"];
$s=$sex==1?'true':'false';//没必要处理
//造对象
$db=new mysqli("localhost","root","","aaas");
//判断连接是否正确
!mysqli_connect_error() or die("链接失败！");
//写SQL语句
$sql="update info set name='{$name}',sex={$sex},nation='{$nation}',birthday='{$birthday}' where code='{$code}'";
//执行SQL语句
$r=$db->query($sql);
if($r)
{
header("location:0613chaxun.php");
}
else{
echo "修改失败！";
}
