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SQL Server: Difference between PARTITION BY and GROUP BY
I've been using GROUP BY for all types of aggregate queries over the years. Recently, I've been reverse-engineering some code that uses PARTITION BY to perform aggregations. In reading through all the documentation I can find about PARTITION BY , it sounds a lot like GROUP BY , maybe with a ...
How to tell if browser/tab is active [duplicate]
... called every second that I only want to run if the current page is in the foreground, i.e. the user hasn't minimized the browser or switched to another tab. It serves no purpose if the user isn't looking at it and is potentially CPU-intensive, so I don't want to just waste cycles in the background....
Modify table: How to change 'Allow Nulls' attribute from not null to allow null
...needing to change multiple columns to allow null, then you will need to perform separate ALTER TABLE .. ALTER COLUMN .. commands
– sonyisda1
Feb 17 '17 at 15:14
...
What does it mean by select 1 from table?
...ially compelling reason not to).
EDIT
There actually is one case which I forgot about until just now. In the case where you are trying to determine existence of a value in the database from an outside language, sometimes SELECT 1 FROM TABLE_NAME will be used. This does not offer significant benefi...
What's the difference between comma separated joins and join on syntax in MySQL? [duplicate]
For example if I were to have a table "Person" with a column "id" that references a column "id" in table "Worker"
5 Answers...
Is there a float input type in HTML5?
... and min), which defaults to 1. This value is also used by implementations for the stepper buttons (i.e. pressing up increases by step).
Simply change this value to whatever is appropriate. For money, two decimal places are probably expected:
<input type="number" step="0.01">
(I'd also set...
Adding devices to team provisioning profile
...
This worked for me:
Login to your iphone provisioning portal through developer.apple.com
Add the UDID in devices
Go back to XCode, open up the Organizer and select "Provisioning Profiles", ensure that "Automatic Device Provisioning" ...
How to use shared memory with Linux in C
...but
// anonymous (meaning third-party processes cannot obtain an address for it),
// so only this process and its children will be able to use it:
int visibility = MAP_SHARED | MAP_ANONYMOUS;
// The remaining parameters to `mmap()` are not important for this use case,
// but the manpage f...
Why use symbols as hash keys in Ruby?
...ls are garbage collected in Ruby 2.2
– Marc-André Lafortune
Jan 20 '15 at 18:28
2
Great answer! ...
How to make an Android Spinner with initial text “Select One”?
...o -1, and proxies the supplied SpinnerAdapter to display the prompt string for position less than 0.
This has been tested on Android 1.5 through 4.2, but buyer beware! Because this solution relies on reflection to call the private AdapterView.setNextSelectedPositionInt() and AdapterView.setSelected...