How to Subtract current date time from date time in database - PHP - php

Question

I'm working on a project.I have to check " how many minutes ago ,user updated the database " .For that I used following code :
<?php
include('connect_db.php');
$sql =" SELECT * FROM test_table WHERE user='john' ORDER BY time_ DESC LIMIT 1" ;
$result = $conn->query($sql);
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
$time = strtotime($row['time_']);
$current=time();
$sub_time=$current-$time;
echo $sub_time;
}
The problem is the code is returning negative values like [ -17173 ].
The date-time stored in my db is like [ 2018-07-14 11:42:21.006515 ]
I simply want to compare current time with the the time stored in database get results in seconds or minutes .
I need help to solve this issue.Thank you .

Answer 1

You can just change your select statement to give you the time difference in seconds as shown below:
$sql =" select UNIX_TIMESTAMP(current_Timestamp()) - UNIX_TIMESTAMP(time_) FROM test_table WHERE user='john' ORDER BY time_ DESC LIMIT 1" ;

Answer 2

I think DateTime is better approach, as it has the methods to achieve the result you need.
maybe something like this:
$time=$row['time_'];
$curr_time=new DateTime();
$difference=$time->diff($curr_time);
http://php.net/manual/en/class.datetime.php

Answer 3

Updated
You should use the DateTime functions to figure out the difference in time. You should be able to integrate this into your code.
I incorporated my suggested code as a function into your original code. This should work for you.
Try this:
function timeDiff($date){
$date = new DateTime(date('Y-m-d H:i:s', strtotime($date)));
$current = new DateTime(date('Y-m-d H:i:s'));
$interval = $date->diff($current);
return $interval->format('%H:%I:%S');
}
include('connect_db.php');
$sql ="SELECT * FROM test_table WHERE user='john' ORDER BY time_ DESC LIMIT 1" ;
$result = $conn->query($sql);
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
echo timeDiff($row['time_']);
}
}

Answer 4

You first need to convert them to timestamp. And them subtract them convert the resuting timestamp back to format you want.
while($row = $result->fetch_assoc()) {
$time = strtotime($row['time_']);
$current=time();
$sub_time=date('d-m-y h:i:s',(strototime(date('d-m-y h:i:s')-$time));
echo $sub_time;
}
You need to handle the greater than and less than cases too.