DESC的MySQL命令挂起； ASC很好

Question

I have a simple MySQL database table with just 20 records. The ID column is an AUTO_INCREMENT integer which is set as the primary key.

This code is trying to fetch the most recent entry from the table, using a PDO object:

$query="SELECT * FROM latest_news ORDER BY ID ASC";

$pdo=connectToDatabase();
$result=$pdo->query($query);

$newsStory=$result->fetch();

This code works fine when I'm sorting ascending ORDER BY ID ASC , but when I sort descending ORDER BY ID DESC , it hangs and loses connection. No PHP error message is displayed; the page never loads in the browser, even after a long wait.

Environment is PHP 5.4.45, MySQL 5.6.27 and a local web server using EasyPHP 14.1

Of course, if any more information is needed, please let me know. Still fairly new to MySQL queries.

Answer 1

This turned out to be due to the result of the MySQL query.

When using DESC , the result was huge, and being processed by another function caused PHP to hang.

The result from ASC was different and smaller, so was not causing the same problem.