How to insert things like “now() -interval '2 minutes'” into PHP PDO query?

Question

I have a query like this: (on Postgresql 8.4, PHP-fpm 5.3.10 (fpm-fcgi))

select * from users where now() - interval \'2 minutes\' < seenlast ORDER BY seen         


        

Answer 1

I don't know much PDO or PHP but I think I know what's going wrong here.

When you say this:

interval '3 minutes'

You're really performing a cast operation that's the same as:

'3 minutes'::interval
cast('3 minutes' as interval)

So what you're doing is casting a TEXT value to an INTERVAL. That means that you need to produce something that looks like the string '3 minutes'. You could paste the string pieces together using string concatenation:

# Use cast to make the precedence cleaner.
$query = $db_conn->prepare("select * from users where now() - cast(:myminute || ' minutes' as interval) < seenlast ORDER BY seenlast"); 
$query->bindParm(":myminute", $mymin)

Or you should be able to do the string wrangling in PHP:

$query = $db_conn->prepare("select * from users where now() - interval :myminute < seenlast ORDER BY seenlast"); 
$query->bindParm(":myminute", $mymin . ' minutes')