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。
Example #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 );
?> 用户评论:
[#1] zjrwjzzz at 163 dot com [2015-02-13 17:03:26]
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";
}
?>