MySQL选择最近4小时内的记录

Question

I have a last_post_time field set up as DATETIME in my user database. I want to check if the current user has a successful post made in the last 4 hours in my PHP file, and if not, do something. Here is what I have:

$query = mysqli_query($con,"SELECT last_post_time FROM xxyyzz_users WHERE ID=$user_ID");
$row = mysqli_fetch_array($query);
$userpost = $row[last_post_time];

if ($userpost == '') { // no post, do this } else { // has a post, do this }

1) How do I add the post time check to my query

2) Is my PHP correct?

Answer 1

You can select only those users directly in your query and return the number of users meeting that criteria

SELECT count(*) as u_count
FROM xxyyzz_users 
WHERE ID=$user_ID
and now() - interval 4 hour <= last_post_time