I am developing a facebookapp where two users play against and the time counts to zero. Whats the best way to do this? I tried to send an ajax request to a php script every second which updates the database with the current time in seconds that the user has left. But sometimes I have 0 values at the columns and the user has no time left. The query strings are ok. Would it be better to store timestamps?
If I would not store the times and the user refresh the page he gets the time back.
Why don't you save the exact timestamp when the clock shows zero?
You can handle all outputs with these one number. You don't have to send requests all the time. Only at first and than when your timestamp reached.
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I need to know how many times a page is viewed in a specific timeframe, say the last 30 days. In the database there is a PageViewCount field so every time the page is viewed, the PageViewCount increases, but there is no timestamp in the database of when this occurs.
I know there has to be a simple solution to this, but I am having a real hard time wrapping my brain around it.
As it is stated, it is impossible to query for such a value. Consider the following equivalent example: I have some coins, for a total of $3.50 and I don't track the movements of the coins. How much money did I had yesterday?
You should have a daily procedure that stores the current PageViewCount with the current date in another table and then simply query that table.
I have an online database CUSTOMERINFO with more than 100k details stored like following format Cust Id, Customer name, Addr, Phone,.......,Call back time
I want to retrieve data when call back time equals current time automatically.
I have designed front end with Java and currently 10 employees working with the database and now they are manually retrieving the data by ID,..
I know select command is very useful to retrieve but I want it to do automatically instead of calling each time manually.
Edited:
When the customer data is retrieved from table, either we will set another call back time or no call back and then pushed into table again.. In the next time if no call back is set in the place of call back time that row no need to be retrieved.
I'm likely missing something here, but:
Something like SELECT ... FROM table WHERE 'Call back time' >= NOW()
I'd recommend not using simply equals, as has been said in the comments, because you might miss items.
If you update the callback time after you have retrieved the callback items, that should work as long as you do not do the query to get callbacks more than once every few seconds.
As was mentioned in the comments, this is just the start though. There are going to be other issues you'll have to deal with.
I'm trying to help a taxi company. The problem is that they have a credit card machine that takes payments, and has its own database entries, and there is a completely separate database that has a list of entries such as pick up time, and drop off time.
I need to match the database of trip entries to the credit card purchases, and the only way to do this is by matching which vehicle is running the transaction, and looking for a time CLOSE TO the DROP OFF time and see if it's a match. It's not ideal.
So, I am trying to compare two times in yy-mm-dd hh:mm:ss format. They need to be plus or minus 5 minutes of each other. How do I do this in MYSQL?
I thought SubTime and Addtime would work, and it seemed to, but then I got wierd results.
SELECT * FROM completedtrans WHERE DrivID = 128 AND TransTime BETWEEN SUBTIME('2013-06-20 16:53:06', '0 00:05:00') AND ADDTIME('2013-06-20 16:53:06', '0 00:05:00')
Here's an example of one of my searches. Can anyone tell me what's wrong with it? It's supposed to search 5 minutes before and after that particular given time. I can't simply write the time, because the query is automatically generated through php code.
I'm quite new to VB and i'm working on a project to record the details of employees clocking in and clocking out. I want to know how to make it so when the 'clock in' button is clicked the time will start recording and when the 'clock out' button is pressed the time will stop recording. Also once clock out is clicked the hours in between clock in and clock out will be recorded and stored into a mySQL database.
This information will be outputted onto a DataGrid showing the time and date of when the employee has clocked in.
Then the amount of hours will be multiplied by a pre-written hourly wage .. which is already stored inside one of the tables in my mySQL database.
Any help would be appreciated.
You should store the event instead of the result.
Store the clock-in time as well as a row for the clock-out time.
Then you will need a procedure either on your database or in the application that will iterate over the rows and match clock-ins to clock-outs.
This approach will let the application crash/terminate and restart without losing data.
Alternatively you could put the clock-in and out in the same record (different columns), and just insert the clock-out into the first row that matched employee and null clock-out.
I would have the clock In button fire an event in the program that created a record for the employee ID I'm assuming you have at that time.
Then once the clock out button is clicked you would fire an event that would go out to your database and pull in the first record it found with the employee ID you are looking for, a valid clock in time and a null for the clock out time. If the program didn't find something that matched all that criteria you would have to handle that however you wanted (I would do the lookup when the employee logged in or whatever and only allow them access to the clock in button if there was no record present and only allow them to use the clock out button if there was a record found for their ID).
Once you have that record in memory you should set the clock out time and calculate the difference using the clock in time that was written to the database earlier.
I would use a stored procedure in the database to handle adding/updating/managing the record and do all the calculations and whatever else you want to do at the time of the clock in/out inside the program itself. But I think its all just preference as far as where the actual processing takes place is concerned.
The most obvious reason for this is that the program can be shut down in between clock in's and clock out's without losing anything at all. If you try to keep track of it all in memory you will lose all your clock in's once the program is shut down for whatever reason(closed manually/"End Task"ed through task manager/unhandled error).
I'm something of a MySQL newbie, and I was wondering if there was any way to set up a notification system so that an e-mail notification would be sent any time an entry hasn't been updated for a specific amount of time (say, 6 months). Preferably, it would be done by specific category rather than row. Any tips?
Thanks!
you can add a field storing the timestamp of the last update, and run daily job (very very small script)