How do I do multiple updates in a single SQL query?

Question

I have an SQL query that takes the following form:

UPDATE foo
SET flag=true
WHERE id=?

I also have a PHP array which has a list of IDs. What is the best way to accomplish this other than with parsing, as follows, ...

foreach($list as $item){  
    $querycondition = $querycondition . " OR " . $item;  
}

... and using the output in the WHERE clause?

Answer 1

This would achieve the same thing, but probably won't yield much of a speed increase, but looks nicer.

mysql_query("UPDATE foo SET flag=true WHERE id IN (".implode(', ',$list).")");

Answer 2

You should be able to use the IN clause (assuming your database supports it):

UPDATE foo SET flag=true WHERE id in (1, 2, 3, 5, 6)