Wanted to ask You how can I setup something on my php website, that would everyday automatically check and compare current date to all the database datetime entries and delete the rows of the dates that are in the past (for ex. if the current date is 2014-03-17, it would delete the rows that have datetime of 2014-03-16 ).
Because I basically have a TV-package website (not a real thing, just for a class), where you can order a package, you enter for how long and it adds that amount to current date, writes the order into database with the date written into a field named "expires". Would it make sense if I just wrote the checking function into the index, so when someone visits the site it would delete it? If so, how could I compare the two dates?
The DB example looks something like this: http://s29.postimg.org/7sbgj2hnr/dbtest.png
Although I highly recommend a scheduled task, you can do it in PHP by calling:
$sql = "DELETE FROM tableName WHERE `expires`<'".date('Y-m-d')."'";
Convert the date to a unix timestamp and compare it against the value of time() like you would any other integers.
Related
I'm a beginner for php and developing this web application, which users who registered on this site, can be claimed some scores in every one hour. When a user claims at some time, database stores that time as time data type in to user_claim_time column. When that same user tries for his next claim, this php script be able to get his last claim time and add one hour to check if the user really claims in an one hour.
So, my question is how can we add one hour to queried time. I'm using php time(h:i:s) function to store server's current time into the database.
You can do something like this:
SELECT * FROM your_table
WHERE user_claim_time < NOW() - INTERVAL 1 HOUR
However i recommend you to use user_claim_time column in datetime format.
Because time like this '00:00:00' will produce negative output as one hour subtraction can change the date or month as well. For example date like this '2017-08-01 00:00:00'.
So using datetime is the right way i think to properly compare time difference.
For default i'm using this snippet in my codes
setlocale(LC_TIME,'it_IT');
and I did save all my dates in mysql in a timestamp format.
In a view of make international one of my codes, i would like to save in MySQL a similar value
2013-07-12T07:59:27+0000
but of course with the +2 hours. So a Polish user will have a +3 and so on...
What's the best field for mysql to store that value? I need also to work with date, from PHP and/or from directly MySQL (for example)
SELECT id WHERE data BEETWEN [...]
Of course if I start with correct way, i don't need to change in future all my dbs, codes, etc...
Thank you very much!
For me is better store date time as UNIXTIME, it avoid the time difference between user from different locations.
You can use:
SELECT * FROM table_name
WHERE field_name
BETWEEN UNIX_TIMESTAMP('2013-07-12 07:59:27')
AND UNIX_TIMESTAMP('2013-07-13 07:59:27')
to get the Date Range
It seems like there are too many complicated ways of doing this, so I'm looking for a clean, succinct answer to this issue.
I write a blog, I click submit, and the title, content, and timestamp INSERTS INTO my blog table. Later, the blog is displayed on the blogindex.php page with the date formatted as MM-DD-YYYY.
So this is my 3 step question:
What is the best column type to insert the date into? (ex: INT, VARCHAR, etc)
What is the best INSERT INTO command to use? (ex: NOW(), CURDATE(), etc)
When I query the table and retrieve this data in an array, what is the best way to echo it?
I'm new at PHP/MySQL, so forgive me if I don't know the lingo and am too frustrated reading 1000 differing opinions of this topic that do not address my issue specifically, or only cover one of the 3 questions...
Here is my opinion on your three questions:
Use the correct data type: Date or DateTime. I would choose for the DateTime type as you store the time as well (might be very handy if you want to have some kind of order, when you added the posts).
It all depends whether you just want the Date (use CURDATE()) or the Date + Time (use NOW()).
You fetch the data and format it how you want it. Don't format it yet in the query, just use the correct PHP functions for it (for example with DateTime). How you fetch the data, doesn't matter too much; you can use PDO or MySQLi or ...
Always store and process dates and times in UTC and perform timezone adjustments in your presentation layer - it considerably simplifies things in the long-term.
MySQL provides a number of different types for working with dates and times, but the only one you need to worry about is DATETIME (the DATE type does not store time information, which messes up time zone conversion as information is lost, and the TIMESTAMP type performs automatic UTC conversion (which can mess up programs if the system time zone information is changed) and has a smaller range (1970-2038).
The CURDATE() function returns only the current date and excludes time information, however this returns information in the local timezone, which can change. Avoid this. The NOW() function is an improvement, but again, returns data in the current time zone.
Because you'll want to keep everything in UTC you'll actually want to use the UTC_TIMESTAMP function.
To return the value you'll need to execute SQL commands in sequence with variables, like so:
SET #now = UTC_TIMESTAMP()
INSERT INTO myTable ( utcDateTimeCreatedOrSomething ) VALUES ( #now )
SELECT #now
Date would probably be the best type, although datetime will work as record more accurate as well.
There isn't a 'best insert into', but what do you really want and how accurate you want the date to be. For a blog, I would say make it datetime and use NOW(). so visitors can see quite accurate of when this post is made.
surely you can easily find huge to run sql and fetch a select query from sql using php by google, so I'll leave this easy work to your self.
For echo the date, you can use the php date format such as:
$today = date("m-d-y"); // 03-10-01
I think Styxxy has it pretty well right, but here is a links for your PHP date formatting part...
How to format datetime most easily in PHP?
(Supporting link: http://php.net/manual/en/datetime.format.php )
Basically it's
echo date("d/m/Y", strtotime('2009-12-09 13:32:15'))
... although, I think the strtotime is unnecessary as it should already have the type of datetime.
In terms of the MySQL, yes, do it as a datetime col, use NOW() as the SQL keyword, and depending on how you want to get it from the database you could...
SELECT CAST(col_name AS DATE) .... or .... SELECT CAST(col_name AS DATETIME) <-- this last one is implied due to the col type.
good luck! :)
In my application I'm developing a functionality for creating "reminders".
A reminder has a date and a time. In my application, I have a form to create / edit reminders - this has two separate fields to input this information:
<input type="text" name="date"></input> <!-- datepicker plugin -->
<input type="text" name="time"></input> <!-- timepicker plugin -->
Now as a rule I have always used a DATETIME column whenever I have needed to store date/time, however this is the first time I'm having to store a user inputted date/time.
I figured it would be best to have seperate DATE and TIME columns, because it would be easier to insert / retrieve the data to / from my application. For example I won't have to combine the values from the two input fields to create a single value to insert in to the database. And likewise I won't have to split a single value in to two values to populate the form fields in edit mode.
But on the other hand won't it be easier to query the table if I used one column? What do you think?
You should build bottom-up (database at the bottom). Don't think about the application, just the database. Now, what makes sense at the database level. DateTime.
So you need to write extra code at the application level.
Please see it
Adding a Timepicker to jQuery UI Datepicker
http://trentrichardson.com/examples/timepicker/
convert your date time according to your mysql format and store it
$mydate = strtotime($_POST['date']);
$myfinaldate = date("d-m-y", $mydate);
$mytime = strtotime($_POST['time']);
$myfinaltime = date("H:i:s", $mytime);
Seperating columns is unlogical. You can use timestamp as datatype and you can use mktime function to parse date and time easily.
Doesn't it depends on the system you're creating.
If you want to store dates beyond 2038 I would store the datetime and time separate.
what if you are developing a reservation application and at one end you need to know on what date and at what time to schedule an appointment for a user, and at the other end, you need to match the user to a doctors schedule. You save the doctors schedule in a database and you need to know (amoung other things) when the doctor is available (on what days), and at what times. Let us forget about the on what days for a moment, and focus on the time shedule first...
You need to develop a programmable schedule so that if you know that the doctor works 6 months in a particular calendar year. (Jan - Jun), He or she may work (9-5 M,W,Fr), and (10-3 T,Th). Sat and Sunday the doctor is off. So you develop a table to hold the Daily time schedule with 2 columns to hold the daily starttime and daily end time for each day of the week. 14 columns in total and a primary and possibly secondary key. So now its time for some date arithmetic (This is where it gets hairy:-|...
You can say i your query: (mySQL)
Select such and such...
where form.theapptdatetime between doctorschedule_startime_tuesday and doctorschedule_endime_tuesday
and this will do a match to see if your datetime is within the date range of your doctorschedulestartime and endtime... but what if all you need is the time??
will the date arithmetic still work if the time value is stored as a datetime???
In other words if I have 01:00:00 as my doctorschedule_startime, is this a legitimate date value for my arithmetic to work, or will a date portion be forced upon me.
Perhaps I should store the time as a varchar, and convert it to a suitable datetime value and perform the arithmetic in the code instead of the query????
An example comes to my mind as to when have date and time split:
You could want to have DATE a part of the unique index, so that a user is only allowed to add 1 record to some table per date, but still you want to know the TIME he added it, so you keep DATE and TIME separate.
I'll explain my goal first: I want the user to query the database, and return rows only if those rows have been updated since their last query. No sense returning data they'd already have. So I created a column called 'lastupdated', a timestamp type which autoupdates every time any content in the row is updated. This works fine. Now, I want to form the query correctly. The user will have their previous query's timestamp saved, and via php will use it to compare their previous query's time with the time each row has been updated. If the row was updated after their last query, the row should be returned.
I made something like this,
SELECT * FROM users WHERE '2011-02-26 01:50:30' <= lastupdated
but its obviously much too simple. I checked the MySQL manual and found this page MySQL Time/Date Page. I'm sure the answer is here, but I've read through it any nothing really makes sense. I have a timestamp in the same format used by the MySQL timestamp type, but I don't know how I will compare them. Thank you very much for your help.
That query is exactly how you'd do it. As long as a stringified date-time is in MySQL's preferred format (yyyy-mm-dd hh:mm:ss), then it will be internally converted into a datetime value, and the comparisons will go ahead.
You'd only need the date/time functions you found if you want to do something more complicated than simple "greater/less than/equal" type comparison, e.g. "any records that have a December timestamp".
As Marc said, your code should work. But you probably want to do this programmatically with a variable for the time instead of the literal.
If you don't have the date-time specified as a string, but rather as a timestamp (e.g. from using the php time() function), then you can use the following query:
$query = "SELECT * FROM users WHERE FROM_UNIXTIME(" . $timestamp . ") <= lastupdated";
The key is the FROM_UNIXTIME() MySQL function.