大约有 47,000 项符合查询结果（耗时：0.0231秒） [XML]
In SQL, how can you “group by” in ranges?
... 9 then ' 0- 9'
when score between 10 and 19 then '10-19'
else '20-99' end as range
from scores) t
group by t.range
or
select t.range as [score range], count(*) as [number of occurrences]
from (
select user_id,
case when score >= 0 and score< 10 then '0-9'
wh...
Cannot make a static reference to the non-static method
...n. Consider this class (psuedocode):
class Test {
string somedata = "99";
string getText() { return somedata; }
static string TTT = "0";
}
Now I have the following use case:
Test item1 = new Test();
item1.somedata = "200";
Test item2 = new Test();
Test.TTT = "1";
What are ...
Set transparent background of an imageview on Android
...
If you add any number from 01 to 99 before the actual hash code, it will give you the transparency. Eg: Black with more transparency - #10000000 Black with less transparency - #99000000
– AnhSirk Dasarp
Feb 6 '1...
pandas: filter rows of DataFrame with operator chaining
... A B C D
a 1 4 9 1
b 4 5 0 2
c 5 5 1 0
d 1 3 9 6
In [99]: df[(df.A == 1) & (df.D == 6)]
Out[99]:
A B C D
d 1 3 9 6
If you want to chain methods, you can add your own mask method and use that one.
In [90]: def mask(df, key, value):
....: return df[df[key]...
What would be C++ limitations compared C language? [closed]
...n a project I'm working on, this is what happens if you just swap gcc std=c99 for g++:
sandiego:$ g++ -g -O1 -pedantic -mfpmath=sse -DUSE_SSE2 -DUSE_XMM3 -I src/core -L /usr/lib -DARCH=elf64 -D_BSD_SOURCE -DPOSIX -D_ISOC99_SOURCE -D_POSIX_C_SOURCE=200112L -Wall -Wextra -Wwrite-strings -Wredundant...
Objective-C : BOOL vs bool
...
199
From the definition in objc.h:
#if (TARGET_OS_IPHONE && __LP64__) || TARGET_OS_WATCH...
What does the C++ standard state the size of int, long type to be?
...one of these de facto standards is legislated by the C standard (ISO/IEC 9899:1999), but all are permitted by it.
And, by definition, sizeof(char) is 1, notwithstanding the test in the Perl configure script.
Note that there were machines (Crays) where CHAR_BIT was much larger than 8. That meant, ...
What does the restrict keyword mean in C++?
...commends it's usage when available:
restrict keyword
! New to 1999 ANSI/ISO C standard
! Not in C++ standard yet, but supported by many C++ compilers
! A hint only, so may do nothing and still be conforming
A restrict-qualified pointer (or reference)...
! ...
Circle drawing with SVG's arc path
Short question: using SVG path, we can draw 99.99% of a circle and it shows up, but when it is 99.99999999% of a circle, then the circle won't show up. How can it be fixed?
...
In Objective-C why should I check if self = [super init] is not nil?
... that if (self != nil) check is there, for proper operation of your class, 99.99% of the time you actually do need self to be non-nil.
Now, suppose, for whatever reason, [super init] did return nil, basically your check against nil is basically passing the buck up to the caller of your class, where...