大约有 40,000 项符合查询结果（耗时：0.0819秒） [XML]
How to add column if not exists on PostgreSQL?
...statement:
DO $$
BEGIN
BEGIN
ALTER TABLE <table_name> ADD COLUMN <column_name> <column_type>;
EXCEPTION
WHEN duplicate_column THEN RAISE NOTICE 'column <column_name> already exists in <table_name>.';
END;
END;
$$
...
How to determine the content size of a UIWebView?
...he wrong frame size by the fitting size. This sounds terrible but it's actually not that bad. Since we do both frame changes right after each other, the view isn't updated and doesn't flicker.
Of course, we have to wait until the content has been loaded, so we put the code into the -webViewDidFinis...
what is the unsigned datatype?
...or unsigned long long int
— float
— double
— long double
— _Bool
— float _Complex
— double _Complex
— long double _Complex
— atomic type specifier
— struct or union specifier
— enum specifier
— typedef name
So in case of unsigned int we can either writ...
set date in input type date
...swered Nov 10 '12 at 14:30
int32_tint32_t
4,51511 gold badge1919 silver badges1616 bronze badges
...
Sorting dictionary keys in python [duplicate]
...
my_list = sorted(dict.items(), key=lambda x: x[1])
share
|
improve this answer
|
follow
...
Colon (:) in Python list index [duplicate]
... Does not work with dictionaries. applying d[:5] is the eqivalent of d.__getitem__(slice(0, 5, None)). A slice is not hashable.
– Steve Zelaznik
Jul 4 '15 at 2:31
7
...
C/C++ 如何向上取整？ - C/C++ - 清泛网 - 专注C/C++及内核技术
...上取整？一般地，向上取整有两种方法：#include <math.h>int _tmain(int argc, _TCHAR* argv[]){int a = 6, b = 5; ceil函数printf("%d...一般地，向上取整有两种方法：
#include <math.h>
int _tmain(int argc, _TCHAR* argv[])
{
int a = 6, b = 5;
//ceil函数
prin...
tinygrad：不到1000行代码的深度学习框架，天才黑客开源GitHub 2.3k+ stars...
...rt Tensor
import tinygrad.optim as optim
from tinygrad.utils import layer_init_uniform
class TinyBobNet:
def __init__(self):
self.l1 = Tensor(layer_init_uniform(784, 128))
self.l2 = Tensor(layer_init_uniform(128, 10))
def forward(self, x):
return x.dot(self.l1).re...
Async Image Loader Extension：异步图像加载器扩展 - App Inventor 2 拓展...
...)]1108×320 33 KB
[color=var(--tertiary)][color=var(--secondary)]IMG_20240505_161351[color=var(--secondary-high)]760×760 90.2 KB
[color=var(--tertiary)][color=var(--secondary)]IMG_20240505_161331[color=var(--secondary-high)]679×679 103 KB
https://community.appinventor.mi ... r...
Set value to NULL in MySQL
... can be inserted/updated without quotes:
INSERT INTO user (name, something_optional) VALUES ("Joe", NULL);
UPDATE user SET something_optional = NULL;
share
|
improve this answer
|
...