【发布时间】：2015-06-30 15:56:49
【问题描述】：
当我使用以下代码时，我无法插入数据。它显示以下错误消息：
[插入数据时出错。请稍后再试。您的 SQL 语法有错误：请查看与您的 MySQL 服务器版本相对应的手册，以在第 10 行的 ')' 附近使用正确的语法]
if($_SERVER['REQUEST_METHOD'] != 'POST')
{
$sql = "SELECT
cat_id,
cat_name,
cat_description
FROM
categories";
$result = mysql_query($sql);
if(!$result)
{
echo 'Error while selecting from database. Please try again later.';
}
else
{
if(mysql_num_rows($result) == 0)
{
//there are no categories, so a topic can't be posted
if($_SESSION['userlevel'] == 1)
{
echo 'You have not created categories yet.';
}
else
{
echo 'Before you can post a topic, you must wait for an admin to create some categories.';
}
}
else
{
echo '<form method="post" action="">
Subject: <input type="text" name="topic_subject" />
Category:';
echo '<select name="topic_cat">';
while($row = mysql_fetch_assoc($result))
{
echo '<option value="' . $row['cat_id'] . '">' . $row['cat_name'] . '</option>';
}
echo '</select>';
echo 'Message: <textarea name="post_content" /></textarea>
<input type="submit" value="Create topic" />
</form>';
}
}
}
else
{
//start the transaction
$query = "BEGIN WORK;";
$result = mysql_query($query);
if(!$result)
{
//Damn! the query failed, quit
echo 'An error occured while creating your topic. Please try again later.';
}
else
{
//the form has been posted, so save it
//insert the topic into the topics table first, then we'll save the post into the posts table
$sql = "INSERT INTO
topics(topic_subject,
topic_date,
topic_cat,
topic_by)
VALUES('" . mysql_real_escape_string($_POST['topic_subject']) . "',
NOW(),
" . mysql_real_escape_string($_POST['topic_cat']) . ",
" . $_SESSION['userid'] . "
)";
$result = mysql_query($sql);
if(!$result)
{
//something went wrong, display the error
echo 'An error occured while inserting your data. Please try again later.' . mysql_error();
$sql = "ROLLBACK;";
$result = mysql_query($sql);
}
else
{
//the first query worked, now start the second, posts query
//retrieve the id of the freshly created topic for usage in the posts query
$topicid = mysql_insert_id();
$sql = "INSERT INTO
posts(post_content,
post_date,
post_topic,
post_by)
VALUES
('" . mysql_real_escape_string($_POST['post_content']) . "',
NOW(),
" . $topicid . ",
" . $_SESSION['userid'] . "
)";
$result = mysql_query($sql);
if(!$result)
{
//something went wrong, display the error
echo 'An error occured while inserting your post. Please try again later.' . mysql_error();
$sql = "ROLLBACK;";
$result = mysql_query($sql);
}
else
{
$sql = "COMMIT;";
$result = mysql_query($sql);
//after a lot of work, the query succeeded!
echo 'You have successfully created <a href="topic.php?id='. $topicid . '">your new topic</a>.';
}
}
}
}
`
【问题讨论】：
-
您能否将您的代码示例简化为一个示例？您在这里给我们的 PHP 对 mysql_query() 有 7 次不同的调用 - 失败了？
-
除了使用 PDO 或 mysqli 之外，我在这里要做的就是在执行查询之前将查询打印出来， echo $sql; $result = mysql_query($sql);那么问题出在哪里就很清楚了。
-
你检查 $_SESSION[userid] 在你的第二个 sql 函数中定义了吗？