第十天

1.sql查询

select表示要进行查询，'.'去出所有字段，FROM table 目标数据表，where数据过滤条件，ORDER BY排序条件，LIMIT 取出数量，常用于分页。

查询前.png

查询后.png

2.全部代码演示

gbook.php

<?php
$host = '127.0.0.1';
$dbuser = 'root';
$pwd = '';
$dbname = 'php10';
$db = new mysqli($host, $dbuser, $pwd, $dbname);
@ini_set('date.timezone','PRC');//将PHP的时区改为北京时间
//检查是否成功
if( $db->connect_errno <> 0){
    echo"数据库连接失败";
    echo $db->connect_error;
    exit;
}

$db->query("SET NAMES UTF8");

$sql = "SELECT * FROM msg ORDER BY id DESC";
$mysqli_result = $db->query( $sql );
if($mysqli_result === false){
    echo "sql错误";
    exit;
}
$rows = [];
while( $row = $mysqli_result->fetch_array() ){
    $rows[] = $row;
}
?>
<!DOCTYPE html>
<html>
<head>
    <meta charset='UTF-8'/>
    <title>留言本</title>
    <style>
    .warp{
        width:600px;
        margin:0px auto;
    }
    .add{overflow: hidden;}
    .add .content{
        width:598px;60
        margin:0px;
        padding:0px;
    }
    .add .user{
        float:left;
    }
    .add .btn{
        float:right;
    }

    .msg{margin:20px 0px;background: #ccc; padding:5px;}
    .msg .info{overflow: hidden;}
    .msg .user{float:left;color:blue;}
    .msg .time{float:right;color:#999;}
    .msg .content{width:100%;}
    </style>
</head>
<body>
    <!--发表留言内容-->
    <div class='warp'>
            <div class='add'>
        <form action='formsave.php' method='post'>
                <textarea  name= 'content' class='content' cols='50' rows='5'></textarea>
                <input name='user' class='user' type='text'/>
                <input class='btn' type='submit' value='发表留言'/>
        </form>
        </div>
            
        <?php
        foreach( $rows as $row ){
        ?>
            <!--查看留言内容-->
            <div class='msg'>  
                <div class='info'>
                    <span class='user'><?php echo $row['user'];?></span>
                    <span class='time'><?php echo date('Y-m-d H:i:s',$row['intime']);?></span>
                </div>
                <div class='content'>
                    <?php echo $row['content'];?>
                </div>
        </div>
        <?php
        }
        ?>
    </div>
</body>
</html>

forsave.php

<?php

include('input.php');
include('connect.php');

$content = $_POST['content'];
$user = $_POST['user'];

$input = new input();

//调用函数，检查留言内容
$is = $input->post( $content );
if( $is == false ){
    die('留言内容的数据不正确');
}

//调用函数，检查用户名
$is = $input->post( $user );
if( $is == false ){
    die('用户名的数据不正确');
}


//var_dump($content,$user);
//第九天将留言写入数据库



$time = time();
$sql = "INSERT INTO msg (content, user, intime) values ('{$content}', '{$user}',     '{$time}')";
$is = $db->query($sql);
//var_dump( $is );
header('location: gbook.php');
?>

input.php

<?php
  class input{ 
//定义函数，对数据进行检查
    function post($content){
        if ($content == ''){
            return false;
        }

        //禁止使用的用户名
        $n = ["张三","李四","王五"];

        foreach($n as $name){
            if($content == $name){
            return false;
            }
        }

        return true;
    }
 }
?>

connect.php

<?php

//预先定义数据库连接参数
$host = '127.0.0.1';
$dbuser = 'root';
$pwd = '';
$dbname = 'php10';

//连接到数据库
$db = new mysqli($host, $dbuser, $pwd, $dbname);
//检查是否成功
if( $db->connect_errno <> 0){
   echo'数据库连接失败';
   echo $db->connect_error;
   exit;
}
//设定数据库数据传输的编码
$db->query('SET NAMES UTF8');

//编写SQL
//$sql = 'insert into msg (content, user, intime) value ('1', 'user', 12345)';
$sql = "SELECT *FROM msg ORDER BY id DESC";

//执行SQL
$mysqli_result = $db->query( $sql );

if($mysqli_result === false){
    echo 'SQL错误';
    exit;
}
/*
首次调用显示最新的一条记录
重复调用，依次显示后面的记录
如果没有记录可以显示，就返回null

row = array(0,1,2) == true;
row = null ==fasle;
*/
$rows = [];
while( $row = $mysqli_result->fetch_array( MYSQLI_ASSOC ) ){
$rows[] = $row;
}
var_dump($rows);
?>

命名空间.png

最后编辑于：2020.08.30 11:14:18