I need to get all the entries that were added 'today', ie 24 hours prior to the point of execution. It is simple enough to do so with date column, which I don't have. Is it at all possible to find these rows without such column?
Thanks
No, you can't do it. If you don't have a date stamp on the row, then there's no way of knowing when it was inserted.
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I am stuck on a problem I have with MySQL, I am quite new to it so please have patience :D. I have a table that includes a column with specific dates (each date has multiple entries) and I would like to create a new column with a specific day (Monday, Tuesday, etc.) based on the date I already have. I found a function WEEKDAY I would like to use, but I can't find a way to update all the rows automatically.
I already ADD COLUMN "day" (which is empty now) and need to add the values for all rows. The table has a thousand rows so there is no way I would do it manually one by one. I am sure there is a way around doing it by SQL code. Would appreciate it if anyone can give me a hint.
Thanks a lot!
I want query a table to find the changed rows last day. But there is no explicit time filed in column name. Is there any way I can access these data?
Without a field indicating when a record was changed there is no way to determine when a record was changed, therefore it is unfortunately impossible for you to query the records changed yesterday.
I have a table that I use for statistical purposes.
Its columns are id and 1,2,3,..,31 and pivot.
This table gives the number of views on each day for the last 31 days.
1 gives the number of views for yesterday.
14 gives the number of views for 14 days ago.
etc ...
(pivot is just used to calculate the number of views)
I would use a cron job every day to update this table, but how would I go about "shifting" all the values to the side ( value column 15 would become value column 16; new value for column 1; delete value for column 31)
Define a table with only two columns — "date" and "views"
INSERT a new row in the table with the view count for that day when the CRON job runs
Modify your application query to read through this new table over a custom date range, which could be 31 days or anything else either — please have a look at this link to get an idea:
MySQL Query - Records between Today and Last 30 Days
Not really sure how pivot is being used here. However, I'm almost certain that if you're using it to store the sum of the views, it could as well be computed by using SUM() or GROUP BY without having to need a separate column in the table
As far as data archival / removal is concerned, your daily CRON job could be modified to include a DELETE query (as the last step) which cleans up records older than a certain date. Again, you could use the link above to get your "target" date
.
I apologise that this might sound like a little too long a solution to what you've asked for. However, I feel, this approach should help you organise and maintain the table in question in a better way.
I am trying to write a query to extract records updated in the last 2 hours in SQL Server 2008.
Could anyone help me write this?
select * from table where table.date1>=dateadd(hh,-2,getdate())
dateadd() function lets you subtract hours from getdate() letting you choose records updated past 2 hours
First, you have to design the table so you have a field where the time of the last change will be stored
Then, whenever you update a row, update the value in the 'last update' field. After that, you can use a script such as suggested by Vijaykumar
The downside of this method is that when a single record was changed more than once in the specified time period, you will be notified only about the time of the last update.
Another solution for tracking the updates is to read the database online transaction log file, but you'll need a third party tool for that
I added a new column to a table called price_request_date because I now need to track the date each one was made. I made it so new ones enter the current date when they insert a new row. I was just wondering if there was any way to fill in the previous rows with the dates they were entered? I don't know if MySQL keeps track of that sort of thing or not, but worth an ask. Thanks!
There is not. There is no way to automatically backdate a timestamp field with the original creation date if it weren't already set at creation time.
Frustrating - I know.
nope. it is good to always include LastChgID and LastChgDate on tables like this, do that next time from the get go...