Question

我为我的婚礼网站制作了一个歌曲请求表格，并希望在POST到数据库之前检查我存储表格输入的变量是否为空。我的目标是简单地防止在关闭for时将空行添加到mysql db。

 <?php 
// extract data from form; store in variable
$artist =  $_POST["artist"];
$song = $_POST["song"];

// connect to server 
$conn = mysql_connect('host', 'user', 'pass');


// check if you can connect; if not then die

if (!$conn) {
    echo "<center>";
    die('Could Not Connect: ' . mysql_error());
    echo "</center>";
    }

// check if you can select table; in not then die

$db = mysql_select_db('database', $conn);

if (!$db) {
    echo "<center>";
    die('Database Not Selected: ' . mysql_error());
    echo "</center>";
    }

// Define the query to inser the song request
$insert = mysql_query("INSERT INTO Songs (Artist, Song) VALUES ('$artist', '$song')");  

// check if above variables are empty 
if (!empty($artist) and !empty($song)) {
    echo "<center>";
    echo "Insert was succesful<br>";
    echo "<a href='index.html' target='_self' >Back</a>";
    echo "</center>";
}
else {
    echo "<center>";
    die("Please fill in at least the artist name");
    echo "</center>";
}

// close the connection to the server
mysql_close($conn);
?>

我在一个名为insert.php的文件中有上述内容，当提交索引页面上的表单时会触发该文件。表单使用POST提交并且工作得很好，但是我想阻止空白提交。

编程很新，想学习如何做到这一点。

感谢您的耐心等待。

Answer 1

作为编程新手，我会给你使用mysql_*函数给人们的经典信息：

Please, don't use mysql_* functions in new code。它们不再被维护and are officially deprecated。请参阅red box？转而了解prepared statements，并使用PDO或MySQLi - this article将帮助您确定哪个。如果您选择PDO here is a good tutorial。

但是，作为您问题的直接答案：在插入结果后进行验证，而不是之前验证。 另外，如果您使用mysql_ *函数，请记住清理（使用mysql_real_escape_string）您插入数据库的任何内容。清理输入将阻止SQL injections并删除一些漏洞问题。

if($errors) {
    // there are errors, don't submit to database
    // run through error display process

} else {
    // submit to database
    $insert = mysql_query("INSERT INTO Songs (Artist, Song) VALUES ('$artist', '$song')");
}

Answer 2

你真是太近了！所有你需要做的就是检查艺术家和歌曲是否填写后插入插页！

<?php 
    // extract data from form; store in variable
    $artist =  $_POST["artist"];
    $song = $_POST["song"];

    // connect to server 
    $conn = mysql_connect('host', 'user', 'pass');

    // check if you can connect; if not then die

    if (!$conn) {
        echo "<center>";
        die('Could Not Connect: ' . mysql_error());
        echo "</center>";
    }

    // check if you can select table; in not then die

    $db = mysql_select_db('database', $conn);

    if (!$db) {
        echo "<center>";
        die('Database Not Selected: ' . mysql_error());
        echo "</center>";
    }

    // check if above variables are empty 
    if (!empty($artist) and !empty($song)) {
        // Define the query to inser the song request
        $insert = mysql_query("INSERT INTO Songs (Artist, Song) VALUES ('$artist', '$song')");  

        if($insert) {
          echo "<center>";
          echo "Insert was succesful<br>";
          echo "<a href='index.html' target='_self' >Back</a>";
          echo "</center>";
        }
    }
    else {
        echo "<center>";
        die("Please fill in at least the artist name");
        echo "</center>";
    }

    // close the connection to the server
    mysql_close($conn);

就是这样！

Answer 3

使用空应该就够了。还有isset

http://php.net/manual/en/function.isset.php

Answer 4

嗯，您已经与empty核对了。只需在插入之前移动它并采取相应的行动

if (empty($artist)) {
    echo "<center>";
    die("Please fill in at least the artist name");
    echo "</center>";
}

或检查两者

if (empty($artist) or empty($song)) {
...
}

Answer 5

首先通过函数验证变量或使用if语句

if (!empty($artist) && !empty($song))
 { $insert = mysql_query("INSERT INTO Songs (Artist, Song) VALUES ('$artist', '$song')");}

php：在运行INSERT查询之前检查变量是否为空

5 个答案: