选择某些MySQL字段并使用php显示它们

So what I want to do is I want to search for a certain name in a column called 'filename' and display the 'count' on that row.

This might help explain:

I want to search for Packages in the 'filename' column but I want to display the 'count' on it (4)

id filename count

1 Packages 4

2 Another 7

$filename = 'Packages';
$result = mysql_query("SELECT `count` FROM `downloads` WHERE `filename` = $filename");

Also note that if the filename can come from user input you have to be aware of injection attacks.

$filename = 'Packages'; // From user

$filename = mysql_real_escape_string($filename);
$result = mysql_query("SELECT `count` FROM `downloads` WHERE `filename` = $filename");

Here is an example that selects all Filenames and counts and lists them in a table:

$result = mysql_query("SELECT `filename` `count` FROM `downloads`");
?><table><tr><td>Filename</td><td>Count</td></tr><?php
while($row = mysql_fetch_assoc($result)){
    ?>
    <tr><td><?php echo $row['filename']; ?></td><td><?php echo $row['count']; ?></td></tr>
    <?php
}
?></table><?php

$count = mysql_num_rows($result)
echo($count)

Check out the PHP mysql documentation for more. In particular you'll want to learn about the fetch() functions, which you'll use to display the data you retrieve with your query.

the raw query would be:

select count( filename ) from downloads;

Edit: Okay, you want to loop them onto the page:

foreach( $result as $i )
{
  if( !empty( $i ) )
  {
     echo "<div>$i['column_name']</div>";
  }
}

$query = "SELECT count FROM downloads WHERE filename='Packages'";

EDIT:

$result = mysql_query($query, $con) or die(mysql_error());

$arr_down = mysql_fetch_assoc($result);

echo $arr_down["count"];

UPDATE: For one or more rows with 'Packages' in it, you can show the results in a table like this:

$con = mysql_connect("localhost", "MySQL_username", "MySQL_password") or die ("Unable to connect to MySQL Server " . mysql_error());

$fname = "Packages";

$query = "SELECT filename, count FROM downloads WHERE filename='" . $fname . "'";

$result = mysql_query($query, $con) or die(mysql_error());

$html = "<table>
<tr><th>Filename</th><th>Count</th></tr>
";

while ($row = mysql_fetch_assoc($result)) 
    $html .= "<tr><td>" . $row['filename'] . "</td><td>" . $row['count'] . "</td></tr>
";

$html .= "</table>
";

echo $html;

Assuming what you actually wants is a report of download counts for each filename, you need to use the GROUP BY clause in your SQL statement:

<?php

$res = mysql_query('SELECT id, filename, COUNT(*) AS count FROM downloads GROUP BY filename');

if (is_resource($res)) {
    while (false !== ($row = mysql_fetch_assoc($res))) {
        printf('%d - %s - %d', $row['id'], $row['filename'], $row['count']);
    }
}

?>