大约有 47,000 项符合查询结果（耗时：0.0603秒） [XML]
Round to 5 (or other number) in Python
...
I don't know of a standard function in Python, but this works for me:
Python 2
def myround(x, base=5):
return int(base * round(float(x)/base))
Python3
def myround(x, base=5):
return base * round(x/base)
It is easy to see why the a...
Does use of final keyword in Java improve the performance?
...s, HotSpot keeps track of whether the method has actually been overridden, and is able to perform optimizations such as inlining on the assumption that a method hasn't been overridden - until it loads a class which overrides the method, at which point it can undo (or partially undo) those optimizati...
How to resize superview to fit all subviews with autolayout?
My understanding of autolayout is that it takes the size of superview and base on constrains and intrinsic sizes it calculates positions of subviews.
...
Why does an NSInteger variable have to be cast to long when used as a format argument?
...le on OS X (64-bit), because on that platform NSInteger is defined as long and is a 64-bit integer. The %i format, on the other hand, is for int, which is 32-bit. So the format and the actual parameter do not match in size.
Since NSInteger is 32-bit or 64-bit, depending on the platform, the compile...
Table header to stay fixed at the top when user scrolls it out of view with jQuery
...esign an HTML table where the header will stay at the top of the page when AND ONLY when the user scrolls it out of view. For example, the table may be 500 pixels down from the page, how do I make it so that if the user scrolls the header out of view (browser detects its no longer in the windows vi...
How can I enable the Windows Server Task Scheduler History recording?
...inly .bat files calling PHP files. I have 2 users on the server, one Admin and the other is a Standard user.
8 Answers
...
Postgres: INSERT if does not exist already
...
Postgres 9.5 (released since 2016-01-07) offers an "upsert" command, also known as an ON CONFLICT clause to INSERT:
INSERT ... ON CONFLICT DO NOTHING/UPDATE
It solves many of the subtle problems you can run into when using concurrent operation, which some other answers propose.
...
Getting distance between two points based on latitude/longitude
I tried implementing this formula: http://andrew.hedges.name/experiments/haversine/
The aplet does good for the two points I am testing:
...
Xcode 5: Code signing entitlement errors
... new application which is going to support IOS 7. I got the new XCode 5 GM and tried to sign my apps using my fresh provisioning profile and distribution certificate, but i'm having trouble with distribution. I constantly get the following error:
...
SQL Server reports 'Invalid column name', but the column is present and the query works through mana
...ables with the same name. One is owned by the schema 'dbo' (dbo.PerfDiag), and the other is owned by the default schema of the account used to connect to SQL Server (something like userid.PerfDiag).
When you have an unqualified reference to a schema object (such as a table) — one not qualified by...