Be aware that if you are trying to foreach the associative array returned by mysql_fetch_array() with MYSQL_ASSOC or mysql_fetch_assoc(), you have to ensure the return value that is used in foreach structure is exactly a array rather than a FALSE value.
Or you might encounter the warning below:
Warning: Invalid argument supplied for foreach()
Here is an example (assume that $result have already stored the return value from mysql_query()):
If you have some block of code like:
<?php
// Printing results in HTML
echo "<table>\n";
while ($line = mysql_fetch_array($result, MYSQL_ASSOC)) {
echo "\t<tr>\n";
foreach ($line as $col_value) {
echo "\t\t<td>$col_value</td>\n";
}
echo "\t</tr>\n";
}
echo "</table>\n";
?>
If this is the case, you should use the code below instead:
<?php
// Check ahead, before using it
if (mysql_num_rows($result) > 0) {
// Printing results in HTML
echo "<table>\n";
while ($line = mysql_fetch_array($result, MYSQL_ASSOC)) {
echo "\t<tr>\n";
foreach ($line as $col_value) {
echo "\t\t<td>$col_value</td>\n";
}
echo "\t</tr>\n";
}
echo "</table>\n";
}
?>
MySQL 扩展概述范例
这个简单的范例展示了如何连接、执行一个查询，打印结果集后断开 MySQL 数据库的连接。
示例 #1 MySQL 扩展概述范例
<?php
// 连接、选择数据库
$link = mysql_connect('mysql_host', 'mysql_user', 'mysql_password')
or die('Could not connect: ' . mysql_error());
echo 'Connected successfully';
mysql_select_db('my_database') or die('Could not select database');
// 执行 SQL 查询
$query = 'SELECT * FROM my_table';
$result = mysql_query($query) or die('Query failed: ' . mysql_error());
// 以 HTML 打印查询结果
echo "<table>\n";
while ($line = mysql_fetch_array($result, MYSQL_ASSOC)) {
echo "\t<tr>\n";
foreach ($line as $col_value) {
echo "\t\t<td>$col_value</td>\n";
}
echo "\t</tr>\n";
}
echo "</table>\n";
// 释放结果集
mysql_free_result($result);
// 关闭连接
mysql_close($link);
?>
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zjrwjzzz at 163 dot com ¶
9 years ago
