php MySQL - 无法跳转到 MySQL 结果索引的第 0 行
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MySQL- Unable to jump to row 0 on MySQL result index
提问by Zabs
I have got an old site that has recently been displaying an error which is weird as its been untouched for some time. I get the following:
我有一个旧网站，它最近一直显示一个错误，这很奇怪，因为它有一段时间没有受到影响。我得到以下信息：
Unable to jump to row 0 on MySQL result index 8
What is the cause of this and how should I fix it?
这是什么原因，我该如何解决？
It is a PHP/MySQL site.
它是一个 PHP/MySQL 站点。
回答by nickb
If I remember correctly, this error typically stems from a code segment like the following:
如果我没记错的话，这个错误通常源于如下代码段：
// You probably have some code similar to this
$var = mysql_result( $result, 0, 'column_name');
Where either the query fails or the column doesn't exist. Check that $resultis a valid MySQL resource to make sure that the SQL is valid, then make sure you're actually getting results from the database before trying to call mysql_result.
查询失败或列不存在的地方。检查这$result是一个有效的 MySQL 资源以确保 SQL 有效，然后确保在尝试调用mysql_result.
Or, better yet, using mysql_fetch_arrayinstead of manually fetching every column value (if you have multiple columns returned from the query).
或者，更好的是，使用mysql_fetch_array而不是手动获取每个列值（如果您从查询返回了多个列）。
回答by Minras
Try analysing the result before fetching it. If result is empty, skip fetching.
在获取结果之前尝试分析结果。如果结果为空，则跳过获取。
$result = mysql_query("SELECT * FROM table1");
if (!$result || !mysql_num_rows($result)) {
die('Empty set.');
}
while ($row = mysql_fetch_array($result)) {
// Your code here
}
