PHP，单项查询及多项查询

先封装对象
class DBDA
{
public $host = "localhost"; //数据库地址
public $uid = "root"; //数据库用户名
public $pwd = "123"; //数据库密码 //执行SQL语句,返回相应的结果的方法
//参数：$sql代表要执行的SQL语句,$type是SQL语句类型0代表查询1代表其他,$db代表要操作的数据库
public function Query($sql,$type=0,$db="mydb")
{
//1.造连接对象
$dbconnect = new MySQLi($this->host,$this->uid,$this->pwd,$db);
//2.判断连接是否出错
!mysqli_connect_error() or die("连接失败！");
//3.执行SQL语句
$result = $dbconnect->query($sql); if($type==0)
{
return $result->fetch_all();
}
else
{
return $result;
}
}
}

单项查询页面

<h1>汽车查询页面</h1>
<br />
<?php
include("./DBDA.class.php");
$db = new DBDA(); $cx="";
$value="";
if(!empty($_POST["name"]))
{
$name = $_POST["name"];
$cx = " where Name like '%{$name}%'";//查询字符串
$value = $name;
}
?>
<form action="test.php" method="post">
<div>
请输入名称：<input type="text" name="name" value="<?php echo $value; ?>" /> &nbsp;
<input type="submit" value="查询" />
</div>
</form>
<br />
<table width="100%" border="1" cellpadding="0" cellspacing="0">
<tr>
<td>代号</td>
<td>汽车名称</td>
<td>价格</td>
<td>油耗</td>
<td>功率</td>
</tr> <?php $sql = "select * from Car".$cx;
$attr = $db->Query($sql); foreach($attr as $v)
{
//处理Name
$rp = "<span style='color:red'>{$value}</span>";
$str = str_replace($value,$rp,$v[1]);
echo "<tr>
<td>{$v[0]}</td>
<td>{$str}</td>
<td>{$v[7]}</td>
<td>{$v[4]}</td>
<td>{$v[5]}</td>
</tr>";
} ?>
</table>

多项查询页面

<h1>汽车查询页面</h1>
<br />
<?php
include("./DBDA.class.php");
$db = new DBDA(); $cx="";
$value=""; $tj1 = " 1=1"; //条件1的判断
$tj2 = " 1=1"; //条件2的判断 if(!empty($_POST["name"]))
{
$tj1 = " Name like '%{$_POST['name']}%'";
}
if(!empty($_POST["brand"]))
{
$tj2 = " Brand = '{$_POST['brand']}'";
} $cx = " where {$tj1} and {$tj2} ";
?>
<form action="test.php" method="post">
<div>
请输入名称：<input type="text" name="name" value="<?php echo $value; ?>" /> &nbsp;
系列：<input type="text" name="brand" />&nbsp;
<input type="submit" value="查询" />
</div>
</form>
<br />
<table width="100%" border="1" cellpadding="0" cellspacing="0">
<tr>
<td>代号</td>
<td>汽车名称</td>
<td>系列</td>
<td>价格</td>
<td>油耗</td>
<td>功率</td>
</tr> <?php $sql = "select * from Car".$cx;
$attr = $db->Query($sql);
echo $sql; foreach($attr as $v)
{
//处理Name
$rp = "<span style='color:red'>{$value}</span>";//让结果重点显示

$str = str_replace($value,$rp,$v[1]);
echo "<tr>
<td>{$v[0]}</td>
<td>{$str}</td>
<td>{$v[2]}</td>
<td>{$v[7]}</td>
<td>{$v[4]}</td>
<td>{$v[5]}</td>
</tr>";
} ?></table>