mysqli_query在phpmyadmin中有效，但在php中无效

问题描述

我已经寻找年龄的答案，很多类似的问题，但没有找到解决方案...

I have looked for an answer for ages now, lots of similar questions but found no solutions yet...

无论如何，我想要做的就是使用mysqli_query从数据库中获取用户的ID，当我在phpmyadmin中使用它时，查询似乎可以工作，但是当我将其用作php脚本的一部分时，查询不起作用.

Anyway,all I am trying to do is get the id of a user from the database using a mysqli_query, the query seems to work when I use it in phpmyadmin but doesn't when I use it as part of a php script.

$username = "bob";

$db = mysqli_connect("localhost", "username", "password", "user_data");

$sql1 = "select id from user_information where username='$username'";
$id = mysqli_query($db, $sql1) or die(mysql_error());

echo $id;

数据库连接工作正常，我能够通过php输入数据.

The database connection works fine, I am able to input data through php.

有什么建议吗? (非常感谢任何人的帮助.)

Any suggestions? (Anyone's help is greatly appreciated).

推荐答案

您无法从mysqli_query打印结果，它是mysqli_resource，并且要转储错误，您需要将mysql_error()更改为mysqli_error()

you can't print the result from mysqli_query, it is mysqli_resource and for dumping the error you need to change mysql_error() to mysqli_error()

$username = "bob";
$db = mysqli_connect("localhost", "username", "password", "user_data");
$sql1 = "select id from user_information where username='$username'";
$result = mysqli_query($db, $sql1) or die(mysqli_error());
while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) {
    echo $row['id'].'<br>';
}

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