Im building a simple web page. on loading the page the first time I store the current time in a database. When the page is loaded again I want to get the time that has past since the first load.
I figured out I probably have to use SUBTIME to achieve this. so basicly it would be something like this:
$result = mysql_query("SELECT SUBTIME('now()','time')"); // in this case time is the name of the database row.
I looked around on the net but cant find an example that explains me how to do this. Hope anyone can help me out.
Greetings!
If 'time' is the name of your database column use backticks instead of quotes to get the value:
$result = mysql_query("SELECT SUBTIME(NOW(),`time`) AS `total_time`");
NOW() should not be in quotes.
I would not use MySQL for this.
retrieve the time from your database
$starttime = strtotime($row['time']); // hopefully a datetime value
$endtime = time();
$totaltime = $endtime - $starttime; // gives the time in seconds
and then write it back into your database table, or whatever you want to do with that info
Related
I have the following at the top of every page so when the website is loaded by anyone PHP deletes any record in a specific database table that is older than 3 days.
$conn = getConnected("oversizeBoard");
mysqli_query($conn, "DELETE FROM postedLoads WHERE date < DATE_SUB(DATE('m-d-Y'), INTERVAL 3 DAY");
The problem is nothing is being deleted.
The data type for my date column is varchar(20) and when I insert a date into MySQL it is entered using date("m-d-Y"). The name of my date field is date. So it appears that the above query would be correct, but I have done something wrong, and I am not certain as to what since every example I've looked at has basically looked the same except they used now() instead of date() but I use a specific date format so I can't use now() in my query.
What have I done wrong?
I even tried putting it into a function:
function deleteOversizeRows() {
$conn = getConnected("oversizeBoard");
mysqli_query($conn, "DELETE FROM postedLoads WHERE date < DATE_SUB(DATE('m-d-Y'), INTERVAL 3 DAY");
}
deleteOversizeRows();
Try to provide date by calculating first and then use it in query like below
$date = date("m-d-Y", strtotime('-3 day'));
$conn = getConnected("oversizeBoard");
mysqli_query($conn, "DELETE FROM postedLoads WHERE date < '".$date."');
It might help you. If need any other solution or help, do ask here.
Use MySQL function TIMESTAMPDIFF(unit,datetime_expr1,datetime_expr2);
Function calculates difference between two dates and returns output based on the unit parameter passed .
Try this:
DELETE FROM postedLoads WHERE TIMESTAMPDIFF('DAY',date,now())<3;
For detailed info of function:http://www.w3resource.com/mysql/date-and-time-functions/mysql-timestampdiff-function.php
MySQL table "flightSched" is connected to time, similar to the one below:
flightNo |day |time |arrivalTimeSec
=============================================
WERE112 |Tuesday | 1:00 |1381186800
FGHG234 |Tuesday |23:00 |1381266000
CGHF345 |Tuesday |00:00 |1381183200
I have a mysql query that select all data between two times. This is the query:
$CurrentTimeMinus30min = date('H:i', strtotime('-30 minutes')); //Current Time minus 30minutes
$CurrentTimeMinus30min = strtotime($CurrentTimeMinus30min);
$CurrentTimePlus4Hours = date('H:i', strtotime('+240 minutes')); //Current Time plus 4 hours
$CurrentTimePlus4Hours = strtotime($CurrentTimePlus4Hours);
$query = $mysqli->query("
SELECT * FROM flightSched
WHERE day = '$currentDay'
AND arrivalTimeSec
BETWEEN '$CurrentTimeMinus30min'
AND '$CurrentTimePlus4Hours'
");
I was advised to used strtotime() function on the time values to be able to use them in a BETWEEN MySQL query. This doesn't seem to be working at all.
Where am I going wrong with this query? Any help will be appreciated.
today I found the same problem with yours (mine about coordinates).
and I found out that in some case, a BETWEEN operator can only be used like this
..... WHERE columname BETWEEN smallervalue AND biggervalue
previously I've tried with the biggervalue at front since I dealt with negative numbers, and it fails.
you might found the same problem with your timestamp.
strtotime returns a timestamp so passing that into the MySQL query, like above, won't work. Try using FROM_UNIXTIME instead.
$query = $mysqli->query("SELECT * FROM flightSched
WHERE day = '$currentDay'
AND FROM_UNIXTIME(arrivalTimeSec) BETWEEN FROM_UNIXTIME($CurrentTimeMinus30min) AND FROM_UNIXTIME($CurrentTimePlus4Hours) " );
EDIT - I hadn't noticed that arrivalTimeSec was also a timestamp. The above mightn't be a workable answer for you, but try it. If it doesn't work, as others say, define what you mean by
This doesn't seem to be working at all.
Is it not returning any rows? Is it returning an error? Can you print out $CurrentTimeMinus30min and $CurrentTimePlus4Hours? Narrow down the potential areas for problems.
Have you tried to encapsulate the between? This could potentially solve your problem:
SELECT * FROM flightSched
WHERE day = '$currentDay'
AND (arrivalTimeSec BETWEEN '$CurrentTimeMinus30min' AND '$CurrentTimePlus4Hours')
Also why not just do:
$CurrentTimeMinus30min = strtotime('-30 minutes');
Or
$CurrentTimeMinus30min = strtotime(date('Y-m-d H:i:00', strtotime('-30 minutes')));
Please send us some examples of what your variables are generating.
Your time calculation with date("H:i",...) and strtotime(..) seems to actually produce the correct results, although there is a much easier way to add/substract n minutes from the current time:
$now = time();
$currentTimeMinus30min = $now - 30*60; // 30 minutes * 60 seconds
$currentTimePlus4Hours = $now + 4*60*60; // 4 hours * 60 minutes * 60 seconds
(I assume your time entries in your database are unix timestamps.)
Your query looks fine, too, but there are a few things to keep in mind:
You have redundant fields in your database (day and time can be calculated from the timestamp)
Working with time variables can easily lead to confusion, as the time passes on and if you have no entries in your database that match the specified time range (-30m to +240m) the result set is empty. So to test the query update the database with current time stamps.
I would suggest the following:
Drop the redundant columns day and time and just use the timestamp as base for your calculations, because the day and time is already included in the timestamp. So just use a simple query like
select * from flightShed
where arrivalTime between $begin and $end
have a database with data and time
example: 2013-06-04 08:20:00
need to convert that to
example: 1378478351000
so i can add that number to jquery script event calendar
when i use this php code
$exc_date = $row_Recordset1['exc_date'];
$exc_date = microtime(true) *1000 ;
echo $exc_date;
it works right but it shows me the current date and time not the date and time saved at database,
can somone please help , thanks
If you want to avoid the calculations in PHP, add a computed column using unix_timestamp and str_to_date to your query:
select (
unix_timestamp(str_to_date(TimeStrColumnName, '%Y-%m-%d %H:%i:%s')) * 1000)
as utime,
# ... the rest of your query as before
if the MySQL column is already a date/time field (instead of a string), this will do it:
select (unix_timestamp(TimeStampColumnName) * 1000) as utime,
# ... the rest of your query as before
Of course it does, as you overwrite the database values in the second line by putting microtime instead in it.
You will not be able to get the microtime, when you just have the format of date in the database - so you should use 0. microtime is returning the value of the actual microtime at the moment.
You should do something like that to get time + microtime:
$exec_date = strtotime($row_Recordset1[exec_date"]) . "000";
More information here. The problem with this is, that you will get it as a string, so you will need to convert it to an integer:
$exec_date = (int) $exec_date;
Hope it helps you.
I'm wanting to display on a php page the difference between the current server time and a datetime row plus a row that has milliseconds in it, so I guess the equation would look kind of like ((Datetime+Milliseconds)-Server Time).
The only problem is, I'm not sure how to do it in code. I can currently get the difference between the datetime row and the current time with echo strtotime($row['date_added']) - time(); When I try adding the row that contains the milliseconds, date_mil, I get a really long number.
The date in the row date_added looks like 2012-05-25 16:55:06 and the value of the date_mil is around 218238.
I'm still learning how to do all of this, and this has me confused. Thanks for the help!
I just solved my own problem.
$difference = time() - strtotime($row['date_added']);
$milliseconds = round(($row['date_mil']) * .001);
echo $milliseconds - $difference;
all - fairly simple query question that's been hounding me: How do I query for entries with a date and time only greater than now, or when the query is run (page requested)?
I've seen some examples but they aren't good enough for me to modify. Here's my code:
$todaysDate = date("Y-m-d h:i:s");
$params = array('select'=>'*', 'limit'=>3, 'orderby'=>'t.event_StartDate ASC', 't.event_StartDate < "$todaysDate"' );
An example of the variable "t.event_StartDate" outputs "2010-12-10 22:18:42" so I assume that may be how it's saved in the database.
I suspect I'm not building the date correctly or I need to be using a time function I'm not familiar with in MySQL. Help? This is for outputting a series of events with date and time.
I think you reverse the use <, it should be >
try
SELECT ... WHERE t.event_StartDate>NOW();
/* you don't even need to set $todaysDate */
t.event_StartDate > NOW() don't will returns nothing? a date higher of now lol. I'm confused.