I am setting up a system using PHP and MySQL in which users can add posts to specific days (all posts will be grouped by day).
So When a user goes to the main page, the user will see all of the posts for that day.
Now the problem - Time-zones:
What if I have 2 users, who are 3 hours apart.
User A will post at 12:00 AM, which will add the post to that specific day.
User B, who is in a different time zone, so for this user, it will still be the previous day, say 9:00 PM, will not see the post from user A since user B is still in the previous day in his time zone - this is fine.
Now, when user B gets to the next day (the same day as user A, meaning + 3 hours), he should see all of the posts for that day, but here is the problem:
For user B, user A's posts were added to the previous day, which means that user B will not see user A's post (when user A posted, it was 9:00 PM for user B on the previous day).
So the problem is with the time of the post, I'm not sure how to set this up, and I may be thinking about it all wrong - I actually have a feeling that I am missing something very basic in the logic.
I have searched for similar puzzles but did not really find anything that helped.
Any ideas and/or solutions will be greatly appreciated!
Related
I have created my first php system, it basically is a list of customers which the user can select and log work for which generates a PDF work record.
I want to extend it to generate an invoice every Thursday midnight and send it to the business, eg:
User 1 has worked:
Customer a - 1 hour
Customer c - 2 hours
Customer D - 4 hours
Total 7 hours at (Chargeable rate).
Now in my head it seems pretty straight forward but I want to sense check it with people it possible:
When the PDF is generated I need to store the information in a new table, User ID, Customer name, Hours worked, Time & date. Then each Thursday I need a script to run which will transfer the entries from the database (over the past X days - could I say from ID X which was the last ID to be ran in the previous pdf?) to a PDF, save the pdf to the server and email it to me.
A few questions:
Would It be beneficial to clear this data after X day so the DB doesn't get too big?
What is the best way to ensure that an entry doesn't get missed? I will most likely run the script every thursday at midnight, but I'm guessing theres room for error there if somebody submits an entry at the same time? (slim chance but possible)
I'll be using mPDF for the invoice generation which I already use.
For an art project I am trying to set up an order site.
The concept allows users to book a max. of two time slots with each artist. There are 12 slots per artist, but each slot with a specific definition (so each is unique). The slots are only available for a very limited time and hopefully booked fast. So there will be a lot of requests in a short period of time. I have to make sure each article/slot is only offered to a single user at a time and cannot be double booked.
My idea was, to check for the next unbooked slot(s) (status="free) and on that request update the status of the corresponding row in the table to status="locked". If the user proceeds to actually book the slot, the status is updated to "booked".
If a user clicks "cancel" I can release the article by updating the row to status="free".
However, it is not unlikely that users just abandon the site and I don't see a way to check for that. The slot would remain "locked". I was thinking, there might be a way to automatically reset the status e.g. 120 seconds after is was "locked" and show a countdown to the users. This could even enhance the excitement factor.
I don't think a cron job would work as I need the anchor to be the last update of the row and not a specific datetime.
I looked into MySQL events but understood that I cannot manipulate the data of the table it is attached to.
I would greatly appreciate any ideas.
Thanks,
Sam
In your db your status table add a datetime field.
When someone lock a slot you also save the current time using NOW()
When someone consult the slots you perform and update and free the inactive slots
Update slots
SET locked = false
WHERE `datetime`> NOW() - INTERVAL 15 MINUTE;
SELECT *
FROM slots
WHERE locked = false;
I am creating a system that requires a schedular for a particular task. Users may pick from times 24 hours a day, 7 days a week.
I came up with a few options for the database storage, but I don't think either one is the most efficient design, so I'm hoping for some possible alternatives that may be more efficient.
On the user side I created a grid of buttons with 2 loops to create the days, and the times, and I set each a unique value of $timeValue = "d".$j."-t".$i;
So d1-t0 will be Saturday at Midnight d3-t12= Tuesday at Noon, and so forth.
So, in the database I was first going to simply have a ID, day, time set up, but that would result in a possible 168 rows per event
Then I tried an ID, day, and time 0-23 (a column for each hour of the day) And I was simply going to have a boolean set up. 0 if not selected, 1 if it is.
This would result in 7 rows per event, but I think querying that data might be a pain.
I need to perform a few functions on this data. On each day, list the number of selected times into an array. But I don't believe having a select statement of SELECT * from schedule where time0, =1 or time1= 1 .... ect will work, nor will it produce the desired array. (times=(0,3,5,6,7...)
So, this isnt going to work well.
My overall system will need to also know every event that has each time selected for a mass posting.
"Select * from table where time = $time (0-23) and day= $day (1-7)
Do action with data...
So with this requirement, I'm going to assume that storing the times as an array within the database is likely not the most efficient way either.
So am I stuck with needing up to 168 rows of data per event, or is there a better way I am missing? Thanks
Update:
To give a little more clarity on what I need to accomplish:
Users will be creating event campaigns in which other users can bid on various time slots for something to happen. There will likely be 10-100 thousand of these campaigns at any one time and they are ongoing until the creator stops them. The campaign creators can define the time slots available for their campaign.
At the designated time each day the system will find every campaign that has an event scheduled and perform the event.
So the first requirement is to know which time slots are available for the campaign, and then I need the system to quickly identify campaigns that have an event on each hour and day and perform it automatically.
I am developing ecommerce store in php and I have some problem in creating a logic. The problem is I have a store page where I am showing some products. all the products have some time interval,after interval passes the products will no longer be display there.
For example
Product: jeans
time left: 10 days.
after 10 days jeans product will no longer be there. in database I have a set a field with the name active_status which accepts Y or N..
I know that I can simply run the update query and set the status to "N" after time passes. here in this example after 10 days
BUT the question is WHEN DO I RUN THIS UPDATE QUERY ?
should I always check time and run again and again update query and set STATUS TO 'N'??? IS that is the only solution ?
I mean usually we do like for example if customer logins we set some status or any other event but here we are setting the status against checking the time. Hopefully you have understand my question
In the db I am saving the start time and number of days which user puts through the admin panel
My first shot would be cron, php script and properties table (if needed, because for simple uses you could just store expiration date inside business entity).
Cron runs php script periodically (e.g. once a day),
scripts checks if there is anything to delete, based on properties table, or entity properties.
If there is anything to delete, script performs deletion of selected content.
That's all and it is in fact very popular scenario.
More on cron: http://www.pantz.org/software/cron/croninfo.html
Here is my logic i hope it will helps i think
While Publishing the product we have to maintain the time interval of that product for example if you want to display the product for 10 days give 10 days and date of publish product.
By comparing with that date and number of days given for time interval with the present date i.e today's date
Can you check with this
I'm new to PHP and I'm hoping to make a script where a user will get a "coin" every hour that they go on the page. For instance, if a user logs in twice during the same hour, they will only get one coin. But if they refresh the page during the next hour, they get another coin. However, they do not get coins when they do not refresh the page, even if many hours go by.
How would I even start going about doing this? Any help would be extremely appreciated.
Easy... :) If you are using MySQL or something to store the coins, get the time too, when the coin was credited. And each time the page is called, check the time. A pseudo code would be like this:
load(coins);
timeDiff = timeNow - timeLastCredited;
if (timeDiff > 1 hour)
coins++;
save(coins);
In case of PHP, I guess you may do like this:
$coins = getCoins(); // Assuming this function will load the current coins count from DB.
$lastCredit = getLastCoinCreditedTime(); // Should return a DateTime integer.
$timeDiff = microtime() - strtotime($lastCredit);
if ($timeDiff > 60*60*60*1000)
saveCoins($coins+1); // Assuming this function saves the new number of coins.
I'd do it this way:
On each page load (refresh, login, whatever), check to see if the user has already received a coin for the current hour. To do this, you need to know what the current hour is:
$hour = (new DateTime())->format("Y-m-d-h");
This will give a value like "2013-03-25-11" during the 11:00 hour. I'm including the date, since we don't to want skip giving a coin in, say, the 11 o'clock hour just because they were online yesterday at 11:05.
Then you can either:
Add one to their coin total whenever you have a new $hour value (ie. it's not recorded in your database) and save the $hour value, or
Save the $hour value in the database and count the total number of coins earned with a query like SELECT COUNT(DISTINCT hour) FROM table;
The first approach is useful if they're spending the coins on something (ie. you can add/subtract from their "coin account"); the second is useful if you just want a grand total of the number of coins (ie. the total number earned, ever).
I'm going to assume that you have a users table in a database.
If that is the case, you can use a column in the database to update the latest time that a user has gone on the page with php and a query on that page. Then you can set up a cron job that runs every hour that will query the users table and see if the user has viewed the page within the last hour. If the user has viewed the page within the last hour, increment the amount of coins associated with that user.