大约有 46,000 项符合查询结果（耗时：0.0517秒） [XML]
Reference alias (calculated in SELECT) in WHERE clause
...x (or costly to calculate) you should probably consider a computed column (and perhaps persisted) instead, especially if a lot of queries refer to this same expression.
PS your fears seem unfounded. In this simple example at least, SQL Server is smart enough to only perform the calculation once, ev...
How to get names of enum entries?
I would like to iterate a TypeScript an enum type and get each enumerated symbol name, e.g.:
28 Answers
...
Jackson and generic type reference
...is a well-known problem with Java type erasure: T is just a type variable, and you must indicate actual class, usually as Class argument. Without such information, best that can be done is to use bounds; and plain T is roughly same as 'T extends Object'. And Jackson will then bind JSON Objects as Ma...
Secret copy to clipboard JavaScript function in Chrome and Firefox?
...ing about function not defined, so it's definitely not a browser function, and cannot be used in normal JavaScript files. The following functions also seems to work in the JavaScript console, after playing around with it a bit:
clear()
profile()
Running these in the Chrome console reveals th...
Selecting multiple columns in a pandas dataframe
...1 = df[['a', 'b']]
Alternatively, if it matters to index them numerically and not by their name (say your code should automatically do this without knowing the names of the first two columns) then you can do this instead:
df1 = df.iloc[:, 0:2] # Remember that Python does not slice inclusive of the ...
Putting a simple if-then-else statement on one line [duplicate]
I'm just getting into Python and I really like the terseness of the syntax. However, is there an easier way of writing an if - then - else statement so it fits on one line?
...
Linq to SQL how to do “where [column] in (list of values)”
I have a function where I get a list of ids, and I need to return the a list matching a description that is associated with the id. E.g.:
...
Rotating videos with FFmpeg
...ut.mov
For the transpose parameter you can pass:
0 = 90CounterCLockwise and Vertical Flip (default)
1 = 90Clockwise
2 = 90CounterClockwise
3 = 90Clockwise and Vertical Flip
Use -vf "transpose=2,transpose=2" for 180 degrees.
Make sure you use a recent ffmpeg version from here (a static build wi...
Some questions about Automatic Reference Counting in iOS5 SDK
... currently developing an app for iPad. The development started for iOS 4.2 and is now continuing (and I think will be completed) for iOS 4.3.
I just read about ARC in iOS 5, and basically I understood that we will never need to release and retain objects anymore. My questions are:
...
difference between iframe, embed and object elements
...ame>
The iframe element represents a nested browsing context. HTML 5 standard - "The <iframe> element"
Primarily used to include resources from other domains or subdomains but can be used to include content from the same domain as well. The <iframe>'s strength is that the embedded c...