I have found a proper solution to my "problem" but even after reading mysql pages, I don't understand the logic behind it.
I currently store registration information in my system in a "datetime" formatted field in one of my tables (YYYY-MM-DD hh:mm:ss).
When I want to display the data on one of my php pages, simply posting the exact field data shows the format mentioned above.
I would THINK simply using date("Y-m-d",$row["DATE"]) where $row["DATE"] corresponds to the particular row value would return the desired format.
Instead I have to use:date("Y-m-d", strtotime($row["DATE"])).
Why is this? My $row["DATE"] field is not a string in the first place. Should I be able to simple rearrange the data stored in a datetime field? Wasn't that the purpose of rebuilding my entire tableset to accomodate datetime?
MySQL has a built in function called date_format which you can use to display the date how you want to.
SELECT DATE_FORMAT(date_field, '%Y-%m-%d') as date_field FROM table_name
The manual has the list of formats and the variables needed to display it that way. Using this method there will be no need to have PHP convert it etc. Plus it is less code on PHP side for something MySQL can handle easily.
EDIT
Sorry, just read you were looking for an explanation.
PHP's date function takes in a UNIX timestamp, which MySQL is not using. MySQL uses a real date format IE: YYYY-MM-DD HH:MM:SS, as you know, this is to be compliant for years later. The UNIX timestamp has a limited range from something like 1969 to 2037 that it is valid for, which makes it really useful for "timestamping" of items such as a chat box message or items they are not expected to be around post those dates, where as the MySQL DATETIME should not die out until the year changes to 5 digits or the world ends.
Read the WIKI on UNIX timestamp for more information on it.
MySQL does allow you to select dates in unix timestamp format, which allows them to be used more easily in PHP, exactly as you requested.
The previous answer seemed to ignore this point, or downplay it due to the range restriction on the unix timestamp, but if it's what you're looking for...
SELECT UNIX_TIMESTAMP(datefield) as u_datefield FROM table
will give you the date in timestamp format, which you can use as you suggested in PHP:
<?php
$showdate = date("Y-m-d",$row['u_datefield']);
?>
As the previous answer suggests, unix timestamps do have a limited range, so if you need dates prior to 1970 or after 2038 it may not be suitable, but for everyday use today it's great.
The main advantage of using timestamps over date strings is that timestamps can be added and subtracted, which is much harder with a date in string format.
Related
I am querying an API and I got a date like this: "2019-04-17T14:04:24.224-04:00". I suppose this is an iso date. How can I store the year, month and day on a mysql database? I want the following format "dd/mm/yyyy".
Formats are a display concern, that is it's a function of who is looking at the data, so you don't do it until you know who's looking at it. At the point of display you apply the format required by the user's locale, and quite often adjust for their local time-zone as well.
MySQL's DATE column type is expressed in ISO-8601 format like you have, so you should be able to insert that minus everything after the "T".
So either strip that out before insertion and it should be fine.
On display you can use any of the PHP date formatting functions to get the exact format you want. This is often locale specific.
You'll want to be sure that the time expressed is in the correct time-zone. Do any conversion necessary to get it in the right zone before converting to a date or you may find you're getting the wrong date for several hours of the day.
Generally you should:
Store dates as ISO-8601 formatted values in MySQL's native DATE or DATETIME fields and convert to/from localized formats as dictated by user preferences.
Store any time values as UTC and convert to/from local time as dictated by user preferences.
date("d-m-Y", strtotime("2019-04-17T14:04:24.224-04:00"));
Just do this,
Try this!
update TABLENAME
set date_columnname = LEFT(date_present_columnname,10)
I am trying to optimise how I use dates across my SQL/PHP site. I'm familiar with date() and strtotime() functions, and have created projects which have stored data on the server side in both unix and datetime. I know that changing date doesn't use massive amounts of resource, but I'm trying to understand how to code in the most efficient way.
What I'm trying to work out now is what the quickest/most efficient practise is for storing dates on a server, i.e: What is the most effective combination of SQL FROM_UNIXTIME, CONVERT, UNIX_TIMESTAMP and PHP strtotime and date functions, for a typical table involving frequent CRUD of the date fields. Take the following example:
I have an SQL table which contains 3 date columns. All 3 of these can be updated quite regularly by multiple users of the site, and entries are also entered in to it as follows:
mysql_query("INSERT INTO `regular` (
`regularid`,
`propertyid`,
`userid`,
`billdate`,
`billfrequency`,
`enddate`,
`amount`,
`description`,
`payee`,
`payer`,
`lastpayment`
)
VALUES (
'', '{$_POST['propertyid']}', '$varuserid', FROM_UNIXTIME($date), '{$_POST['billfrequency']}', 'FROM_UNIXTIME($edate)', '$amount', '{$_POST['description']}', '{$_POST['payee']}', '{$_POST['payer']}', 'FROM_UNIXTIME($ldate)'
)") or die(mysql_error);
Print "A regular payment for £".$_POST['amount']." has been created<br/>\n";
Entering in to the database I parse the date fields from a user entry form to a variable in mm / dd / yyyy format, validate it with the strtotime() or mktime() functions, and then submit it using from_unixtime.
However, then displaying information from the database I use:
date("d-m-Y", strtotime($val['billdate']))
That means I take a dd/mm/yyyy date format from the user and another one from the database. I then convert these to unixtime using strtotime, and then convert it back to British date format using date - This is surely doubling? if not tripling? the server query.
My question is in 2 parts.
Firstly, is it quickest a) storing all date formats in unixtime in sql and converting to date format through the server side query or b) storing all date formats in date format and converting to unixtime only when accessing them
(I thought the latter would be best, but my example above shows that even doing that I seem to be using more server time than I ought to)
Secondly, could you point me in the right direction for how I should carry out my own time benchmarks of scripts - I'm only really beginning to understand testing as I'm still relatively new to Php, but I'm keen to learn.
Thanks so much!
Use MySQL's "unix_timestamp()", it's short and can be converted to readable full date within a second by using php, bash etc.
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:
$today = date("m-d-y"); // 03-10-01
I think Styxxy has it pretty well right, but here is a links for your PHP date formatting part...
How to format datetime most easily in PHP?
(Supporting link: http://php.net/manual/en/datetime.format.php )
Basically it's
echo date("d/m/Y", strtotime('2009-12-09 13:32:15'))
... although, I think the strtotime is unnecessary as it should already have the type of datetime.
In terms of the MySQL, yes, do it as a datetime col, use NOW() as the SQL keyword, and depending on how you want to get it from the database you could...
SELECT CAST(col_name AS DATE) .... or .... SELECT CAST(col_name AS DATETIME) <-- this last one is implied due to the col type.
good luck! :)
I want to store the date and time that a user performs an action on my website into a MySQL database. I'd like to be able to do the following with ease:
Store the date and time as one field in the database
Use a built in PHP or MySQL function to generate the date-time of the action
Store the date-time based on my server's time, and not worry about user timezones.
Order By the date-time field when I query MySQL
Later, display the date-time in many different formats using built in PHP methods
Here are my questions:
What data type should I use in MySQL ( eg. timestamp, datetime ... )?
What method should I use to generate the date-time ( eg. MySQL's now(), PHP's date() ... )?
What PHP method should I later use to format the date-time in various pretty ways ( eg. 23/4/2012, 5pm on Monday, July 2012 ... )?
I would store it as a datetime, not a timestamp.
I normally use the PHP date function and that way if you ever want to store the time relative to the user's timezone you can simply change the timezone based off the user's settings.
When you pull it out of the database, use strtotime() to convert it, then you can use all the date() features to display it however you want. Example:
echo date('F j, Y',strtotime($db_datetime)); //Displays as 'March 5, 2012'
I've struggled with this question for years, and I'm beginning to think that the best way might be to store the time as an integer that represents Unix time (number of seconds from Jan 1, 1970). I've done this and it works fine.
Personally I've never used datetime, and I can't think of a situation when I ever would use this. It just carries too many problems with it.
Timestamp is a lot better, but in MySQL it can't store a date later than 2032.
I would love to hear some serious discussion on this topic, but Stack Overflow might not be the best place for this.
If you set the mysql data type to a non-nullable timestamp, then save rows with a null value for that column, mysql will automatically update the timestamp for you.
As for reading it back out again, you can just use php's strtotime and the date object to get it into the format you need.
You should use the datetime datatype for your requirement.
It will store both the date and time from your input field based on your query.
For retrieving the datetime you can use the mysql's date_format() function or PHP's date() function.
The datetime will always be stored according to the server's time and not on the clients time.
In my php application I have this code:
<?php echo date("d/m/ Y ",strtotime($row["m_date"]));?>
In it, $row["m_date"] is fetching from a database.
The problem is that all the dates are printing perfectly except 27/2/2011. It's printing 1/1/1970 instead.
The date in the database is fine, and prints correctly in a PDF.
I'll assume you're getting the date from the database as the string 27/2/2011 because that's most probably what happens (correct me if I'm wrong).
PHP considers the string 27/2/2011 as being in the m/d/Y format, not d/m/Y and tries to parse under that assumption. Because the date is not valid under that format strtotime returns false. Giving false as the timestamp parameter to date is taken as 0, which is the timestamp for January 1st 1970.
What you need to do is either get your date in another format (or better still, as a timestamp) from the database, or parse it yourself (say using explode).
Good luck,
Alin
The database should be able to return the date to you as a UNIX timestamp. For example, MySQL has the UNIX_TIMESTAMP() function.
SELECT UNIX_TIMESTAMP(date_column) FROM table;
Postgres has date_part
SELECT DATE_PART('epoch', date_column) FROM table;
Most other databases should have similar features. If you can get the date out as a UNIX time stamp you can pass that directly to date() without having to use strtotime() as well.
All of this does of course assume you're using a temporal datatype for the columns in question (timestamp, datetime, timestamp with time zone, etc) and not just storing a string. You are using a temporal type, right? If not, then why not?
if you are storing the date in the database as a timestamp this should work
<?php echo date("d/m/Y",$row["m_date"]);?>
if you are storing the date in the database as a date or datetime this should work
<?php echo date("d/m/Y",strtotime($row["m_date"]));?>
How is the m_date stored in the databases? Is it a datetime object? Or a string.
Problem with strtotime is that it isn't real good at deciphering written dates. So something like 27/2/2011 gives problems while 27/02/2011 gives no problems at all.
So there are 2 solutions:
Make sure all the dates that get entered into the database are of the correct format (dd/mm/yyyy).
Write a regular expression that adds a leading zero to all single characters.