mysqli_real_escape_string无法正常工作

Question

我想这两个使用mysqli_real_escape_string和trim制造的MySQL前一起INSERT查询。我的代码如下：

<?php
$fname = mysqli_real_escape_string($dbc, trim($_POST['fname']));
$sname = mysqli_real_escape_string($dbc, trim($_POST['sname']));
$occ = mysqli_real_escape_string($dbc, trim($_POST['occ']));
$twitter = mysqli_real_escape_string($dbc, trim($_POST['twitter']));
$email = mysqli_real_escape_string($dbc, trim($_POST['email']));
$skype = mysqli_real_escape_string($dbc, trim($_POST['skype']));
$topic1 = mysqli_real_escape_string($dbc, trim($_POST['topic1']));
$topic2 = mysqli_real_escape_string($dbc, trim($_POST['topic2']));
$topic3 = mysqli_real_escape_string($dbc, trim($_POST['topic3']));
$avoid1 = mysqli_real_escape_string($dbc, trim($_POST['avoid1']));
$avoid2 = mysqli_real_escape_string($dbc, trim($_POST['avoid2']));
$avoid3 = mysqli_real_escape_string($dbc, trim($_POST['avoid3']));
$cr = mysqli_real_escape_string($dbc, trim($_POST['cr']));

if ((!empty($fname)) && (!empty($sname)) && (!empty($email)) && (!empty($topic1))) {
    $dbc = mysqli_connect('host', 'user', 'password', 'database') or die('Error connecting to MySQL server');
    $query = "INSERT INTO initial_details (fname, sname, occ, twitter, email, skype, topic1, topic2, topic3, avoid1, avoid2, avoid3, cr) VALUES ('$fname', '$sname', '$occ', '$twitter', '$email', '$skype', '$topic1', '$topic2', '$topic3', '$avoid1', '$avoid2', '$avoid3', '$cr')";
    $result = mysqli_query($dbc, $query);
    if (!$result) {
        mysqli_close($dbc);
        echo 'Duplicate';
    } else {
        mysqli_close($dbc);
        echo 'Success - entry added';
    }
} else {
    echo 'Error';
}   
?>

使用上面的代码，我会收到“错误”消息，但是，如果我删除mysqli_real_escape_string()并仅使用它，trim便能够成功插入我的条目。

为什么mysqli_real_escape_string()在这种情况下我无法使用？

Answer 1

$dbc = mysqli_connect必须先进行所有mysqli_real_escape_string调用才能使其正常工作。这是因为您需要活动的mysqli连接才能使用该功能。